A mermaid and a merman swimming.

Merpeople are mythological creatures that are human/fish-hybrids, the legends of which go back more than three thousand years.


Mermaid Council

Mako's Mermaid Council.

Ancient mermaids used to play an ancient game similar to tug-of-war. A mermaid must use whatever power she has to drive a ship to her side. Ancient mermaids may have used real ships long ago but like the siren songs, using real ships was probably forbidden. However, this view is not shared by all mermaids and some may be fascinated by the land and even can fall in love, just like Sirena, Rita and Mimmi did.

Eons ago, a army of mermen carried the Trident in battle and behaved in a destructive manner until mermaids from each of the five oceans defeated them by drawing on the powers of the oceans and locked the trident away in the Trident Cave with one of the kinder mermen's help.

An unnamed merman built the Merman Chamber on Mako Island. He never activated the Chamber and fell in love with a mermaid. They ruled the seas for years.

The Chinese Mermaid was a member of the Eastern Pod and fell in love with a land boy. Another Eastern Pod heard of this and punished the mermaid and the pod by casting a spell to turn the land boy into a Water Dragon.

Mermen are brought up on land in foster families, go to land school and mingle with humans. Mermen do not have Moon Rings. Mermen no longer have pods since the war between mermen and mermaids.

Aurora threatened the Northern Pod and later redirected her threat to the Eastern Pod. Nerissa came to help them and fought alongside them for years. Nerissa went to face Aurora and was never seen or heard from again. During the battle, Aurora turned Nerissa into the Water Dragon and made her attack the Eastern pod, destroying the Eastern pod. The survivors were forced to flee to the land of China, and eventually the pod split. Having lost all sense of herself, Nerissa was sent to destroy the entire Eastern Pod while she was the dragon. After the Eastern Pod was destroyed, she was put in a deep sleep and Nerissa was believed to be dead by her fellow mermaids.

A pod consisting of over a hundred mermaids took refuge on the reef of Mako Island. When Sirena, Lyla and Nixie are charged with guarding the Moon Pool during the Full Moon Ceremony, a boy named Zac Blakely fell into the pool by accident and became a merman. When the pod found out what happened, they blamed the girls for breaking the rule and cast them out while the rest of the pod fled to the South Pacific where they joined another pod. To correct the problem, the girls broke the rule of using a Moon Ring to go on land, and later the one that forbade singing the Enchantment Song. They then encountered Rita Santos, a mermaid of the pod who had long since found new life on land, and asked her to complete their training. In the end, Rita deemed them worthy of having Moon Rings.

Rita teaching the girls how to create a storm

Rita teaching the girls.

With Zac Blakely being a merman, after he returns the Trident to the chamber he becomes a temporary member of the little pod formed by Sirena, Nixie, and Lyla. While Rita doesn't share their adventures, she is considered part of their pod due to her involvement with the girls in guidance and training. Sirena, Mimmi, Ondina, Evie, and Zac form a little pod in Season 2. Erik, being a merman, becomes a temporary member of the little pod formed by Mimmi, Ondina, Evie, and Zac.

The Canadian Mermaid was caught on footage singing the Northern Pod Enchantment Song. Sirena saw it and was enchanted and sang it to David before Mimmi and Ondina sang the Counter-version song which broke the enchantment.


Mermaids and Girl Mermaid in Moon Pool

Four mermaids in their true forms.

Mermaids have long orange tails and a matching top. Their tails are covered in scales and end in a classic dolphin-shaped fluke. They also have a short dorsal fin running along the backs of their tails from their waists to a little more than halfway down their tail.

Mermen have a long blue tail covered in scales that ends in a fluke that differs to that of mermaids. They also have a short dorsal fin running along the backs of their tails from their waists to a little more than halfway down their tail.

Erik Merman

A merman in his true form.

When the Legs Spell breaks, merpeople lose their clothes they're wearing in human form which only reappear when they become human again. Their hair keeps its natural length, but any hair-ties, headbands, hair clips or hairspray disappears, along with their clothes. When they dry, their hair returns to whatever hairdo it was in. Moon Rings, as magical objects, remain even if they are under the Legs Spell or in their true forms.

A merperson's tail is also very strong, this is shown when Emma saves Zane Bennett by smashing in the steel door on Miss Chatham's boat, or when Nixie breaks the frozen surface of the pool in the underwater entrance to the Grotto.

The transformation also occurs when merpeople are exposed to snow or ice, but since Southern merpeople never interact with snow, they will also develop Snow Rash and become feverish. The only way to cure them is by applying dried seahorse powder onto their skin. Northern, Western, and Eastern merpeople are immune to Snow Rash. Northern merpeople born and raised in icy waters are presumably resistant to the cold since they swim in colder waters around Canada and the Arctic Circle.

In H2O: Mermaid Adventures, mermaids have different colored, glittering tails, different with accessories in their hair that match their tops, and silver or gold armbands on both of their arms.

While the original live action show only ever shows merpeople holding their breath while underwater, the sequel has specifically stated that merpeople can breathe underwater. H2O: Mermaid Adventures reveals that merpeople can also speak underwater. Also, merpeople are shown to be able to hold their breath for more than fifteen minutes at a time if needed, with no noticable discomfort.


Although considered as the same creature, mermaids and mermen have different behaviors. Mermaids are determined to learn more about their powers and master to control them, instead of gaining more. They even have Mermaid School, which teaches their young how to use their powers and using them wisely. They live in pods and are never alone, and aren't really as solitary as mermen (although Lyla is considered a loner, but isn't that solitary and cooperates with the other two). Mermaids usually travel with or hang around in groups of at least two or three other mermaids.

Mermen, on the other hand, are left by their mothers to be raised on land by humans in a adoptive human family, most likely to hide from the mermaids after losing the war to them, which explains why mermaids mentioned that mermen haven't been seen for a while. Originally, both mermaids and mermen lived in groups or pods, but after the great war that happened between mermaids and mermen, mermen no longer lived in pods in the sea. They are described as solitary and territorial. They are also described as power-hungry by the mermaids, and would do anything to obtain power. Zac does not really have this typical mermen behavior, but upon seeing the Trident for the first time, he becomes obsessed with obtaining it. He also believes that he is destined to possess it after he falls into a Moon Spell but then snaps right out of it the moment he touches the Trident for the first time. Unfortunately, after being betrayed by the mermaids, Zac comes to see them as corrupt, trouble-making, selfish, devious, and power hungry. He doubles his efforts to get the Trident and denounces the mermaids as his enemies, vowing to claim vengeance on them for all the trouble they caused him. Later, as the mermaids make many unsuccessful attempts to strip Zac of the Trident, he even goes so far as to try take Mako from the mermaids after he mistakenly believes that they are calling in reinforcements to attack him for the Trident. All of this causes Zac to inadvertently recreate the war between mermaids and mermen and nearly finish the job the mermen of the past began.

Mermaids who fell in love with humans were banished from their pods as it's forbidden for mermaids to fall in love with land people. Natural mermaids can have some difficulty when they obtain legs for the first time, but with a lots of practice, they will overcome this issue. For unknown reason, mermaids are also instinctively terrified of cats. However, they can learn to cope with this fear and conquer it like Rita who loves her own feline, Poseidon. Sirena also shows affection to Rita's beloved pet but her friends, Ondina and Mimmi, though they no longer fear cats, they continue to dislike Poseidon.

On their birthdays, mermaids give gifts rather than receive them. Their mothers raise them, but if she has a son, she is forced to give him to adoption to be raised in a foster human family on land. Mimmi was raised by her mother, but at some point she was forced to give her to the Mako Pod until her disappearance. Sirena's only known family member is Aquata, but no other relative as a mother was mentioned, while Nixie, Lyla and Ondina's family were never mentioned. Pods will even accept and raise mermaids from other pods like Mimmi, who is a Northern mermaid raised since a young age at the Mako Pod.

According to Ondina, mermaids share the secret that binds them together, and that mermaids who are in the same pod felt like sisters towards one another, despite having no biological relations. This statement was confirmed as Nixie and Lyla stated that Sirena was like a sister to them. This method also had convinced Rikki to give Weilan and Ondina the Jiao Long Bracelet.


Main article: Pods
Mako Mermaid Pod

Mako Pod

There are pods of hundred of mermaids worldwide, while the Mako Pod consisting of over a hundred. On full moon nights, mermaids all around the world honor the moon with a ceremony. According to Ondina, the Northern Pod knows the best spells and potions. In each pod, there's a Mermaid Council, with Veridia as the Head in the Mako Pod. She makes the laws and rules for the Mako Pod to follow.

Some of these are:

  • It is forbidden to sing the Enchantment Song (exclusive only in the Mako Pod, as it is unknown if other pods allow mermaids to use their ability).
  • It is forbidden to associate with land people.
  • It is forbidden to use a Moon Ring to go on land.
  • It is forbidden to let land people into the Moon Pool, especially during a Full Moon.
  • It is forbidden to fall in love with a land person.
  • It is forbidden to travel too close to land.
  • It is forbidden to reveal their powers to humans.

Mermaids of the pods use the Full Moon as a source of magic and power. They create Moon Rings out of blue moonstone to help increase their magic and can use them to accomplish many complex feats and spells, as the rings can heal injuries but can also cause destruction.

Hatchlings go through training to be worthy of these rings. Mermaid School teaches them to use their powers correctly and to be sensible in the difficult choices made through mermaid life.


Mermaids and mermen lives on a seafood diet, despite being able to eat land food. However, many merpeople think land food and drinks disgusting, choosing to eat prawns and drink sea water instead. Humans that transformed into merpeople still prefer land food, however, they can eat or drink anything a merpeople born in the sea can, like replacing pancakes for raw fish and orange juice for sea water.

Moon Pool

Main article: Moon Pool

The Moon Pool is a special pool that can turn humans into merpeople when the Full Moon passes over. The two known Moon Pools are located on Mako Island near Australia and the Sea Caves of Ireland. These Moon Pools are known to have turned Cleo Sertori, Emma Gilbert, Rikki Chadwick, Isabella HartleyGracie, Louise Chatham, Julia, Charlotte Watsford, and Evie McLaren into mermaids, and broke the Tailless Spell on Zac Blakely.

On special occasions, the Moon Pool reacts to the Full Moon magically and unleashes special effects, such as taking away a merperson's powers, cause changed in their personality, either temporarily or forever, or enhancing a merperson's powers.

Powers and Abilities

Main article: Merpeople Powers

Mimmi, Ondina, and Weilan using their powers

The Moon Pool grants all merpeople powers to a human who jumps alone to it in a Full Moon night, aside from transforming them into a mermaid or merman. When two or more people enters, the Moon Pool grants them individual powers as it chooses. When mermaids and mermen left the pods that they were born, their powers becomes linked with a specific Moon Pool when they are accepted as part of their new pod.

Natural Merpeople Abilities

  • Limited Transformation - When a merperson is completely dry, their tails transform into human legs and they are under a spell. Ten seconds after touching water or by being exposed to snow or ice, they will revert back to their true forms. A long orange tail with a matching top for mermaids and a long blue tail for mermen. All clothing, including tops, accessories etc, are absorbed by the merperson and vanish during their transformation. Only Moon Rings remain in both forms as they are magical themselves. Humans who have changed into merpeople possess this power since their first transformation. Since mermaids who were born in the sea do not have a human form, they can cast a spell to give them legs with the Full Moon or Moon Rings.
  • Amphibious/Enhanced Breath - Merpeople's respiratory system can extract oxygen from both water and air, allowing them to breathe freely both underwater and on land. It was also shown that merpeople can hold their breath for over fifteen minutes with no difficulty or discomfort.
  • Slightly enhanced senses - Merpeople may have slightly enhanced senses suited to life underwater due to living in the sea. To sea born mermaids, land people smell horrible, even the average hygienic human emits this smell but only mermaids can detect it. However, they can get used to the smell. By smelling Rita's supply of squid ink, Lyla could identify where the species of squid came from. In H2O: Mermaid Adventures, mermaids have the same range of hearing as dolphins. With this sound, they can hear things humans cannot but their human half allows them to hear sounds cetaceans can't.
  • Endurance - Merpeople are able to swim for days without exhaustion, something which no human has the stamina to do. They can dive at depths no human could withstand, even with submarines or the most expensive dive equipment.
Mako Mermaids Speed-Swimming
  • Speed-Swimming - It's the ability to swim at an incredible speed, and as such, their bodies is encased in bubbles because of the extremely high speed.
  • Aquatic adaptation - Depending on where they are born and raised, merpeople may be resistant to certain elements in that area. Northern merpeople may be resistant to low temperature as they swim in cold, icy waters like the seas around Canada and the Arctic Circle. The Canadian Mermaid wasn't suffering from the cold or hypothermia, even though she was swimming in an area where the temperature was very low and the humans she attacked were dressed in thick clothing to keep warm, further implying the low temperature and merpeople's cold resistance. Despite this, all merpeople are resistant to the cold of the depths. 
  • Siren Singing - A musical/voice-related magical ability that allows a mermaid to put boys and men into an irresistible, hypnotic trance in which he will follow them wherever they go. Only mermaids can have this ability, and, just like Zoolingualism, this ability can't be learned and only merpeople born in the sea have it.
  • Zoolingualism - Some natural-born merpeople have the unique ability to understand and speak the language of sea creatures (for instance, dolphins and whales). It is unknown if the ability can be learned, but it is unlikely. Nixie, Sirena, and Rita are known for demonstrating this ability with dolphins, while Mimmi also speaks dolphin, humpback and blue whale, and northern penguin. In H2O: Mermaid Adventures, the main characters gain the ability to speak with all sea creatures, including cetaceans, cephalopods, fish, marine reptiles, and crustaceans. Just like Siren Singing, this ability can't be learned and only merpeople born in the sea possess it.

Merpeople Magic

Mimmi Using Moon Ring

Mimmi using her Moon Ring

Main article: Merpeople Spells

Merpeople have a natural gift for spell making or using ingredients found in nature for potions. They make potions to perform things their magic powers cannot like heal wounds, transform animals, grant wishes and neutralize anything, including other spells.

Lewis McCartney found a book, "Mermaid Mythology" that held a recipe for a Mermaid's Potion that could give mermaids the power to grant wishes. It may have possessed more potions like the wish-granting spell.

Mimmi Using Jiao Long Braclet

Mimmi using the Jiao Long Bracelet

Moon Rings are a huge part of mermaid magic and every mermaid is taught how to use one and all receive a ring after they finish Mermaid School. Moon Rings are a vital part of a mermaid's survival as merpeople use them for healing what potions cannot, enhance the natural world for camouflage, grant them human form, and amplify their inherent magical powers. With their rings, mermaids can cast many spells. Mermaids can also craft other magical items like the Jiao Long Bracelet. This has red stones, implying mermaids have altered the magic of the stones for a specific purpose. Rita mentions that only a mermaid can wear the bracelet.


Snow Allergy

Sirena and Lyla with Snow Rash

  • Snow Rash - Southern merpeople in general, such as of the Mako Pod, will be infected with Snow Rash after physical contact with snow. It is followed by several negative symptoms and prevents merpeople from using their powers to warm themselves. A merperson who tries to use his/her power will only generate cold and lower the temperature. The only way to cure Snow Rash is a Dried Seahorse Powder that Rita contains stored within a silver seahorse. To heal, the dust must be sprinkled on the affected part of the skin, and it will immediately disappear. This is because they live in warm and cosy weather, and under normal circumstances never come into contact with snow: Northern, Western and Eastern merpeople are immune to Snow Rash.
Emma Finds The Coral

Dangerous Coral

  • Fish Fever - Is caused by a strange, rainbow-colored coral which houses a poison that affects merpeople, causing them to be overexcited and hungry for seafood, but the more the poison seeps into their system, the more ravenous they get. For Emma, her orange scales turned white and scales even appeared on the skin, her hands became webbed, her nails turned black and later into claws, her skin became more monstrous; her neck sprouted a set of gills, her hair started to turn green, her eyes turned yellow, and she made monster-like noises. Fortunately, she was later cured when Lewis sprayed an antidote developed by Laurie on her.


  • Ambergris - Is an old substance that at one point in time was used to make beauty products such as ladies perfume. It comes from the intestines of a whale and it can be used to attract mermaids. In "Irresistible", Zane Bennett finds some old ambergris which Nate later tries on. The smell from the ambergris makes him stink but it also makes him literally irresistible to Cleo, Emma, and Rikki. Ambergris was also one of the ingredients used in Mimmi's Fifty Moons Potion to try to remove Zac's powers.
  • Allergic Reaction - Mermaids seem to have an allergic reaction to a certain substance of aftershave, which cause their powers to blow uncontrollably when they sneeze. Mermaids also had an allergic reaction to a formula that Lewis created to allow them to get wet while in human form, without transforming. The allergic reaction however only manifested as red spots all over their bodies when mermaids were in their human form. Besides this, Lyla, upon being asked by Dr. Blakely of what sort of allergies she has, she calmly responds with: "Only kelp spores in the Atlantic."
  • Sickness - Merpeople don't get sick, unlike humans. However, they can be infected if they come across a sick land person and can spread it to other merpeople as well. The symptoms involve oozing heat from out of their bodies and breathe fire whenever they sneeze. Rita Santos invented a remedy for such situations after coming across such occasions multiple times. Mimmi, being inexperienced with such situations, tried to concoct a potion, but it only worked temporarily, after which the sick merpeople will feel cold and eventually sneezes snow.
  • Moon Pool's Magic - Moon Pools is what gave merpeople their magical abilities. When a human is transformed into a mermaid or merman, they are magically linked with the Moon Pool that turned them and are susceptible to its effects. If a Moon Pool is destroyed or deprived of its magical Moon water, mermaids and mermen linked with said specific Moon Pool will perish and die with it. Mermaids who once were humans are immune to the magic being deprived of their magical source, by unknown reasons.
  • Water Deprivation - Though under the Legs Spell, merpeople cannot remain dry for so long, and they need to swim regularly in order to stay healthy. If they don't touch water and are completely deprived of it, they will die.

Known Merpeople



Note: † = Deceased


  • Mermaids and mermen born in the sea do not have a human form, although they have the ability to give themselves one casting the Legs Spell with the Full Moon or using a Moon Ring. They also have difficulty getting used to walking at first but with lots of practice, becomes a habit. 
  • Body fluids such as tears and saliva, despite containing a high percentage of water, are not enough to make a merperson transform.
  • Water is much more than a mermaid's home. Water can help heal or revive them. However, this only applies to certain illnesses or injuries as it takes more than water to heal a mermaid who is struck by the Moon Ring or the power of the Trident. Mermaids who stay in the sea don't get sick.
  • The Moon Ring can be used to help heal a mermaid from certain injuries or traumas. Merpeople can speak the languages of certain sea creatures, including dolphin, northern penguin, blue and humpback whale.
  • Merpeople, including those who were born in the sea, are said to have a hard time controlling the power of the full moon when they haven't been properly trained. For this reason, they need to learn to concentrate on letting the moon's magic flow through their bodies rather than resist it. After this, they can wander out in the moonlight.
  • The dangerous reputation of the Northern Pod may have been inspired by the legends of dangerous, wicked mermaids which are most common in the Northern Hemisphere.
  • Mermaid knowledge is limited to the creatures of their oceans. Mimmi was unaware that penguins are only native to the Southern Hemisphere, despite the fact that she actually can talk with them.
  • Mermaid's natural predators are orcas, whales and giant squids. Rita uses these as examples of why a mermaid would require a certain power if she ever came across them.
  • Just like in the legends, natural mermaids have a slight streak of vanity and often comb their hair like the classic depictions of mermaids.
  • Natural mermaids tend to be given names with meanings that relate to water in some way, including literal translations to "water", or relating to mythological figures related to it such as gods, goddesses, and spirits.
  • While merpeople do age, their lifespan is far longer than that of humans - Weilan once stated that that due to Ondina's personality, they would become friends only in " a couple of centuries", which indicates merpeople can live for at least several centuries.


Main article: Gallery: Merpeople

See also

Merpeople Powers
Merpeople Spells
Gallery: Merpeople

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