I found what may either be a bullfrog or a green frog with a badly injured back leg. Its skin is missing, exposing the muscle tissue, fat, and bones beneath, but all of these things seem to be intact. Based on other forums I've seen about setting up a "frog hospital," I set up a clean terrarium with wet paper towels on the bottom and taped to the outsides so he's less stressed out. I've been spritzing him with water too to keep him hydrated. I cleansed the wound with purified water (the stuff you use for new ear piercings etc.), and used bottled spring water with added chlorine neutralizer (specifically for amphibians, not fish), to make it safe for him. It sits in a little bowl for him to sit in.

I'm wondering what advice everyone has for me, and furthermore, how much and often and WHAT he needs to eat. It's the Seventeen year cicada swarm here, so there are plenty of those if he can eat them?

Thank you all so much in advance for your advice! I really want to help him pull through. I can't tell if it's infected already, but there doesn't seem to be any pus or foul-smell.