Animal?

Tiny Tuesday challenge ‘ The animal kingdom’.
Well this is a tiny skull, just 3 inches, and it is / was an animal, but what? Any ideas?

An indoor blip on a dismal, wet, murky day.
We called to see our granddaughter J who is still on holiday from school.
A nice catch-up, and hearing all about their Cornwall Christmas.
She is looking forward to going , with a friend,to the Cat Cafe in Leeds tomorrow.
I hadn’t heard of it, but apparently is is very popular. They had to book two months ago to get in.
Can’t say I would want to have a coffee and cake with cats roaming all around me!
Fortunately J is a cat lover.
Hope they have a good time.