My idea based of the mythical Chimera.
The line has 3 evolutions.
The first is a kitten with a snake instead of a tail, like a small garter snake. It's called Kitmera. The idea is based on the way cat's hiss like snakes. It's also based off feral cats so it's portrayed as constantly aggressive and hissing. It's a fairy type. It evolves into Psymera, it's middle form which sprouts a goat's head, like that of a domesticated goat(which can becomes feral), and the cat's part becomes more like a wildcat, while the snake becomes a larger wild snake. In this form it becomes part Psychic. The final form turns the cat into a full blown lion, the goat's head into a mountain goat, and the snake's tail into a devilish serpent. It's called Chimutant, which is a reference to Chi, the concept of the spirit, and the fact that real life mutants are called chimeras. It exists to show that Fairy types can be monstrous. It's a pseudo-legendary and the explanation for it being so rare is that it's a real genetic mutant since a lot of mythical animals were probably just mutant animals. It's signature move is a bad-ass physical fairy move called Chi Slash which has high critical hit and potential to lower special defense. What's cool about this move is that even though it's Physical and boosted by its huge attack, it attacks the victim's spirit so the damage is calculated on their special defense despite it being a physical move.
It can also learn practically all "elemental" type attacks via TM but naturally learns Fire moves as well.
