Man is he! He has grown into one aggressive fish. I have never owned one like this before. I can not put my hand in the tank without him taking shots. My 2 year old put his finger in the tank this week and got a surprise. Thank God he wasn't hurt but I am guessing it scared him into not putting his fingers in the tank again. If any of you are parents and have ever watched Bubble Guppies you know where we got the name Grumpfish from. Fits him perfectly.