Ben 10 Fan Fiction Wiki
Ben 10 Fan Fiction Wiki

Mermaim is the Omnitrix's DNA sample of a Admiren Scavenger from the Glistening Neptune, the aquatic deep-sea trench of the planet Cupiditatem. He is a free-to-use alien, and exists within the Earth-216 universe, the main universe of Multiverse vs. Tennyson.


Although possessing shape-shifting capabilities and technically no official base form, Mermaim typically manifests as an aquatic humanoid form based off of the depiction of folklore mermaids, but with characteristics inspired by sirens of Greek mythology, with a humanoid upper-body and giant, forked fish-like tail for a lower-body in place of legs. Mermaim's base form features dark-midnight-blue, smooth scales, reflective, aquamarine-blue fins emerging from his scalp, the back of his head, shoulder-blades, the backside of his biceps and thighs, around his lower-neck, forming a collar of sorts, around his hips, forming another similar collar, and the end of his tail, alongside large, bright-green eyes, black gills on the sides of his face, aquamarine-blue lips, five webbed fingers on each hand, and the Omnitrix symbol on the middle of his upper-back, in-between the fins on the back of his shoulder-blades.

Although appearing innocent at first, Mermaim has frightening, retractable characteristics, including gigantic, black, razor-sharp teeth and claws, each tooth and claw with a serrated underside, a long, fleshy tongue, and two rows of sharp, black spines running down his backside, one on each side. In addition, Mermaim's semi-masculine base form can become exaggeratedly feminine, including a voluptuous figure with a shrunken waist, larger lips, black eyelashes, and "puffier" fins.

When seen by an entity immune to Mermaim's abilities, Mermaim resembles an androgynous blob of bright-green light, "waving" around like water, only retaining a few features, including his eyes and the Omnitrix symbol on his backside.

Powers and Abilities

Mermaim's primary ability is his desire-based shape-shifting, which can automatically activate when someone locks eyes with Mermaim, causing him to transform into an exaggeratedly-seductive version of the looker's species and opposite gender, albeit still possessing bright-green eyes and the Omnitrix symbol on his backside. While in this state, the looker will be locked in a hypnotized "lovey-dovey" state of bliss and attraction, before being forcefully drawn toward Mermaim's luring form, allowing Mermaim to attack or for them to be ambushed by an outside force when they're lured in close enough.

While luring prey, Mermaim can additionally reflect light off of his fins to create an entrancing aura of light, and generate frequencies from his highly-complex vocal cords in the form of a "siren's song", both capable of amplifying its luring effects of his shape-shifting ability. Mermaim can still use either of these abilities to lure without shapeshifting, but it's considerably less effective. Even without requiring prey to lure, Mermaim can still activate his shape-shifting ability, although they are typically used for hiding and disguising

Mermaim has huge retractable teeth and claws that can bite and slash holes through solid concrete, its serrated undersides which can aid in additionally tearing through their species' prey's flesh and cartilage, alongside a long tongue that while lacks prehensile capabilities, can be used to swiftly strike prey.

Mermaim also possesses enhanced strength, durability, agility, biting strength, swimming speed, and lung capacity, an immunity to freezing temperatures and poisonous chemicals, and can both breathe underwater and limitedly survive in the vacuum of space, due to not requiring as much air as humans due to his enhanced lung capacity.


Mermaim's base form entirely lacks the ability to walk, due to permanently having a tail and not featuring legs, and can only gain it through shapeshifting.

Mermaim's luring abilities are entirely useless against those of an extremely low intelligence or a general lack of sight, and stated above, will only be seen as a blob of shifting light. In addition, those who lack the ability to hear will be unaffected by Mermaim's luring frequencies, those with extremely high intelligence or an immunity toward hypnosis will be unaffected entirely, and those without a sexual drive toward the opposite sex would not be hypnotized by Mermaim's shapeshifting.

Although Mermaim can willingly extend and retract his sharp teeth and claws, his teeth and claws will automatically extend outwards if Mermaim enters a state of panic or fear, and will not retract until Mermaim escapes this state.

Typically, Omnitrix wielders naturally express feelings of discomfort after using Mermaim's desire-based shapeshifting abilities, and for obvious reasons.

While underwater, Mermaim is weak against extreme heat and scalding temperatures, and his immunity to poisonous chemicals does not apply to gases.

Compared to a Pisciss Volann, a similarly-aquatic species, Mermaim is weaker in terms of strength, making up in his luring shapeshifting ability.




Mermaim is a free-to-use alien, so feel free to use him in your own series.

  • Mermaim is set to appear sometime in Multiverse vs. Tennyson.


  • Mermaim's name is a pun on "mermaid", referencing Mermaim's inspiration, and "maim", which means "wound or injure (someone) so that part of the body is permanently damaged".
  • Mermaim's species of "Admiren Scavenger", specifically the "Admiren" portion, is a combination of "admire", which means "regard (an object, quality, or person) with respect or warm approval", and "siren", also referencing Mermaim's inspiration.
  • Mermaim's planet name of "Cupiditatem" is the Latin translation of "desire", referencing Mermaim's desire-based abilities.
    • The trench Mermaims' species originates from of "Glistening Neptune" lacks any higher meaning, and was just a fancy name that additionally had a few prototype candidates, including "Black Neptune" and "Shining Neptune".
  • Ben 23's name for Mermaim would be "Fishlips", a reference toward Mermaim's alternative feminine appearance while in his base form, and the name of his Pisciss Volann form, "Fish Fingers", a species Admiren Scavengers are somewhat similar to appearance-wise.
  • Mermaim's shapeshifting abilities were originally photokinetic illusions of manipulated light, with Mermaim's base form being his actual appearance, but the idea of Mermaim lacking a true form and instead able to genuinely shapeshift felt more appealing.
  • Originally, Mermaim was a reinvention of Sheelane's species for the Earth-216 universe, but was changed because the creator, WTB wanted to make it into its own species instead.
    • Because of this, Admiren Scavengers and Sheelane's species are very similar appearance-wise, more so than to Pisciss Volann's.
  • If Mermaim was used by a female Omnitrix wielder, Mermaim's base form would instead be feminine with alternatively-masculine features.
    • Non-binary Omnitrix wielders who use Mermaim would get an androgyous base form without any defining sexual characteristics.