Awwww, you are mean!!!! Mine try to eat anything, and I mean ANYTHING that comes into the tank!
My fingers, plastic (don't worry its cleaning and water testing stuff), food (duh to me i guess). Everything, and if I move it towards them they flick away, but they come straight back because they think it is a game, its then that I'm scared they're going to go for the fingers!
I have a small flashlight in the shape of that blue fish from Finding Nemo. Whenever I hold it up to the tank with my biggest dwarf he curls into an attacking position and starts to back up into the middle of his favorite plant.
My GSP nips at the clay pot all the time, thinks it's a fish or something. Also, whenever I am doing waterchanges, he tends to become very curious at the vacuum.
I've had to buy snake feeding tongs to pick out the uneaten food from my brown puffer's tank. He's only two and a half inches long but he lunges for my fingers if I ever put my hand in the tank.
After seeing what he did to a frozen (and thawed) tiger prawn twice his size, I really don't want to be bitten!