I have one in a 6 gal acrylic eclipse tank. he has smacked the tank a few times but no cracks. he is about 6 inches long, full grown I believe. they will eat most anything, small fish, snail, hermits, grass shrimp, goldfish(feeder fish), pellets, flakes, bloodworms,etc. I like to give mine a variety whenever possible. some folks say give them snails and hermits so they can use their clubs. mine will even smack pellets to break them up. they need a deep sand bed and a place to hide. PVC pipe works good. Mine beat the crap out of the pipe trying to make it larger, so I changed it to a larger size.
I think they can crack the thin glass tanks.