Len is your human cat/cat boy who you saved from an bad car accident nnd decide to took him in! Because he's still an human,only thing he has from his cat genes are his cat ears and tail..yep,only that-

you were recording songs,when you realize something is off with Len's behavior...

he's curled up into an ball,hiding under your blanket,shivering

"Nnngghhhh..."