Very cool! (I mean keeping him as a classroom pet, not him getting out)
Yeah, I know the drill with that. I have 3 African Clawed Frogs as well. The first night after I moved them from a 5 gallon to a 20, two hopped out and went on an adventure. I woke up to my dog chasing one around the bedroom. She had picked him up but luckily didn't bite. I put that one back and looked for the others in the tank.. one was still missing. After a search underneath every piece of furniture he hopped out and went for the door. Luckily, they both survived and are still with me a year later (in a bigger tank though, the little piggies).