So, Skullies are basically these animals that wear the skulls of animals as masks. The more dangerous the animal the skull belonged to, and the bigger the skull, the more respect the animal gets. There's Commander Femur, who is a deer. She wears a  baby T-rex skull, as it was the only T-Rex skull that for her. She hides her true gender to the rest of the army.
Here's Kokaa

And Reini

I'm gonna make a lot more of these fluffy bois