Serleena is an evil Kylothian queen who appears as a lesser being but can take on the appearance of anything in sight. She can also shoot what appear to be vine snares from her fingers to grapple and attack.


As the evil leader of the Kylothians, Serleena was initially drawn to Earth several years back when the Zarthans attempted to bring the Light of Zartha to Earth under the watch of the MIB agency. Upon entering the scene, Serleena kills a Zarthan leader and dispaired as what she though was the Light of Zartha, flew into orbit. Over the years she traveled from planet to planet in her search for the shuttle, constantly being disappointed and destroying many worlds in bitter anger. Very soon, she gets contacted by her people to come to Earth and, after landing at New York City Central Park. There, she finds an open magazine showing an attractive Victoria´s Secret model. Indifferently she becomes a copy of the human model to stay on the planet unnoticed.

At the end of her transformation, a thief attacks her with a knife while licking her soft neck to take her behind the bushes to rape her without imagining she's an evil alien in disguise. She responds by laughing and before being attacked, she grabs him by the neck and eats him alive, bloating her stomach. She digests him while licking her fingers and returns to the magazine is to see it again and realize the original woman doesn´t have that huge belly. Thinking seriously about what to do, she decides to return back the bushes, working hard to throw up his clothes. She succeeds and removes all his belongings (except his knife).

She takes his clothes to dress in a way better suiting the location she is in, disguising herself as a bike rider, and begins looking for the Light of Zartha.

She first stops by Scrad and Charlie´s department to find him watching TV and eating junk food. Without them knowing she is Serleena, Scrad & Charlie gets impressed by her beauty, only to have her shove two tentacles into their ears as a bitter reminder of who they were talking to. They talk about finding the light and agree to look for information at a pizzeria nearby while she eats a greasy hamburger. At the pizzeria, Serleena questions an alien who might know the where-abouts of the Light; getting no usefull information, she slices him with her tentacles also she takes the pizza before leaving the pizzeria. She then goes to MIB headquarters, where she seduces a worker by revealing her bra, explaining that she "wants to learn how to be an underwear model since people tell her that she's got real potential". As a distraction, Scrad & Charlie fake a heart attack at the sight of Serleena's sexy lingerie. Next, Serleena uses her many tentacles to take everybody captive, except for Jay and Kay, both of whom escape via being "flushed". Serleena then releases the agency's convicts for some assistance. She then sends a handfull of these convicts after Jay as he attempts to restore Kay's memory. After a quick memory restoration and brief brawl, Kay and Jay discover the Light is actually Laura Vasquez, a worker at the pizzeria and daughter of Zarthan Queen Laurana.

Upon returning to headquarters, Kay is captured by Serleena, who taunts him over the death of his love, Laurana, and she seduces him by sticking her Kylothian tongue in his ear, but Kay is not amused whatsoever. At the same time, Jay stops the countdown of a machine that would launch Laura into space, and shoots Serleena before she can eat Kay. She is seemingly destroyed, but her initial worm form survives. Quickly, she regenerates and steals a futuristic vehicle to chase after the trio of Jay, Laura, and Kay. After an intense chase scene Serleena is tricked into being eaten by the giant worm, Jeff, along with her spaceship.

Thought to be safe from Serleena's wrath, the trio reach a rooftop and prepare a hidden shuttle for Laura to leave on. However, Jeff bursts through the roof and explodes, revealing Serleena in a giant mutated wormlike form. As Jay was thrown around by her tentacles, trying not to be eaten, Kay casually spoke with Laura before shooting Serleena, releasing Jay. After launching Laura, Serleena returned and showed her true form, that of a huge viney plant, and flew after Laura, but Jay and Kay casually shot her with their weapons, destroying her in a bright fireworks display, also avenging the deaths of the humans (except Creepy) and the aliens she had killed, before returning to HQ.