Aggressive ones. <smile> Hope you have a glass tank. I had a puffer that scratched the heck out of my acrylic tank. He went back to the LFS too late. I run a 180 FO with 5 small triggers, a bird wrasse and a "V" tang. (Sorry, just can't hang onto the V's name!) <smile> Believe it or not: the tang is the most aggressive fish I've got these days.
Linda