They're cool looking but I wouldn't get one again unless I had a tank set up just for predators. I had one and he got so big and mean I couldnt even put my hand in the tank to clean it because he'd attack me! Arrow crabs are evil too. But I'd like to have a tank some day with things like an arrow crab, maybe an angler and an eel or something like that. but be careful what you put in with them.