This is Ankh. He's Raya's pet 'Cat' that she found when she was younger. She found the strange creature wandering the streets of the city and took it home.
Ankh isn't a true cat, but a shape shifter from another universe. He travels through the dimensions and universes, changing shape and mass. But he will always appear with big, blank white eyes and no mouth. He does not eat, he does not sleep. He purely exists.
Most people are terrified of his presence, many who have magic in their blood can sence him near by. He often leaves an Ankh symbol as he travels, marking his passage through time and space. That is where the Egyptians of our world got the symbol and it is how they came to worship cats.
If Ankh doesn't like you he leaves behind a strange scent, like old cellars and leaf mould. It's subtle, but you will notice it.
Ankh has a close bond with Raya, often making many beleive she is a Witch. He sometimes follows her everywhere she goes and others will dissapear for months at a time. But he will always return to her, as he has grown very fond of the anthro Wiger.