Questions about my pet lion?!?!?

I have a pet lion named mittens. I'm not sure what to feed him and my parents still don't know I have him upstairs with me and he's been living with me for 3 weeks. My parents have like 20 cats and 15 dogs. I've been feeding him them and they aren't sure why they're disappearing and suspect me of it because I hate those f*ckers. What do I do with mittens?