What is a good lizard for a child?

My 4 year old desperately wants a lizard, and we're considering getting him one. I would be the one taking care of it, but I want something that he can help with. Something that isn't likely to bite or hurt him (although I know there's always a risk of that with any animal). I would also like something that is fairly easy to take care of. I'm willing to do all the necessary research and put in the effort, but I've never had a lizard before. I would also prefer something that doesn't require live food, but that's negotiable. Any suggestions?