Wendy and Gali are a female two headed wendigo, though both do not understand the concept of sharing a body means cooporation, they have no idea what conjoined twins are.
Wendy and Gali share a body from the head down, meaning it's one head, two faces, their heads are joined but not their jaws.
Wendy and Gali are wendigos, meaning conjoined deer skulls for a face/head/mask, fur, with hooves and long claws;
their eyes glow and they have black hair, they also wear tight wrapping as clothes

Wendy: "the two headed wendigo in your backyard"

* a female slim build figure in the senior uniform, with black stockings and no shoes, Ayano and Tetsuya are quite similar when it comes to personality, though there are some minor differences, like Tetsuya being much more lighthearted and mischievous, while Ayano takes her Love life very seriously, to the point of intimidating or even killing her rivals. Tetsuya likes to brag about her ponytail because for the most of their lives, they had the same haircut.*