He killed the small margarita within 2 weeks of getting him. He's responsible for at least 3 snails and 1 hermit now. All kills have been right outside of his favorite cave and the shells remain strewn right outside both entrances as a warning to others that they aren't welcome.
I saw a hermit on the big margarita briefly and wondered if it was being attacked. Later that night, I realized that yes, it was.
The spaghetti worm made a meal out of the margarita snail's body yesterday...
The hermit sporting the new shell.