Someone ate my eel but I don't know who!

My husband brought home a small snow flake eel and placed it in our 90 gallon tank. It has maybe 6 large rocks and several fish. Most of the fish are used to an eel, the ones that I am suspecting is either the Picasso Trigger or the Porc. Puffer, also have tangs, angels and marine grooper.

little fish

Hmmm... I thought my puffer ate my eel too. I usually saw him every night, but noticed one night I didn't see him. The next day I took out all of my live rock looking for him, hoping that he had not been eaten. After all my live rock was out of the tank I remember reading about eels being great escape artists! I looked behind my tank and there he was
. He had escaped from the tank and died. It was terrible!!! I learned my lesson and next time I will make sure that he can't get out.