He eats pellets, frozen anything (bloodworms, brine shrimp, mysis shrimp, beefhear), live blackworms, and flake food. He basically eats anything he can inhale, as long as its pretty small. He can fit big chunks in his mouth, but he can't swallow them. Even small chunks (1/2" long) of earthworm are too big for him to swallow very easily, so he's no threat to other fish (except maybe fry).
Thanks! She's doing really well. She's started eating really aggressively, and actually took her first whole nightcrawler today. She ate 3 in a row earlier, and then another 2 just before I took those pictures.