IC: Gamma World 1e
You can play a humanoid (mutant human), mutant animal or pure-strain human (no mutations). Possibly even an ambulatory plant, though those are supposed to be NPCs I like to open up those to PCs, they can be pretty fun. I ran Mutant Future before which allows you to be robots too, I'm sure I could adapt those rules back to GW. There are a lot of other rule changes and I found it hard to run LoG with MF.