At nevermore, there are a number of different types with unusual abilities, often simply referred to as "Outcasts" as a whole.
Sirens
Sirens can control others with their voice, an ability which is almost entirely suppressed by the amulets they wear, and when underwater can transform into a mermaid-like form with a tail for their lower half and sharp claws. They tend to have good singing voices, and often end up as the "popular people" at school, though some are wary of their ability to control others and distrustful of them.
Gorgons
Gorgons have snakes for hair, and can petrify others with their gaze, though the ability wears off as soon as they look away. Because of this, a gorgon looking into a mirror is fairly dangerous, without someone else to interrupt it they will remain in stone. Many jokingly refer to being petrified by a gorgon as "being stoned".
Psychics
Psychics appear human, but each has a unique ability, such as being able to seeing the future, telekinesis, animate paintings, control animals, etc.
Vampires
Provided blood packs by the school, vampires are effectively immortal. The sun doesn't burn them, but tends to be uncomfortable and does hurt their eyes a fair bit, so most wear dark sunglasses during the day and avoid direct sunlight.
Werewolves
Able to grow their claws and fangs, as well as transform into a full werewolf form during the full moon, werewolves regard their family as their "pack", and face pressure to fit in with other werewolves.
Others
Though the ones listed above are the most common, there are many other types of Outcasts, each with their own abilities and traits. Many tales of mythical creatures and magical abilities that have been passed down are exaggerated accounts of real Outcasts throughout history, plenty of which have survived to the present day, and are welcomed as students at Nevermore.