1. Attempting to take a tooth out cuz why not
2. UH— I MAY OR MAY HAVE NOT BEEN TRYING TO CUT OFF HIS PENIS
3. Mating Season!!........ (You probably know where that was going XD)
4. Testing out his sexuality like a boss
5. MUSCLES
6. Do his parts grow back in hooman form?
7. TURN HIM INTO A FEMALE
I'm pretty sure those are all of the experiments I tried on Eren bwahahahahahaaaaaa