I just got a new MBU puffer a few weeks age it is about 5 inches long.I heard that they were very aggressive and was going to keep it in my 400 gallon Brackish water tank,but when I put it into my tank everything was chasing and nipping at till it went to the top corner of the tank and I took it out.I have large Mono Sabie reg mono and assorted scats.I put in my tank in the basement with a six inch Tigrenes cat.I have read that they like crabs snails and clams,but the only thing it eats is Minnows and after he eats a bunch it just sits on the bottom.I was wondering if this is normal for them when they are small,I was expecting a more outgoing fish with a personality.No one goes down stairs all day maybe that is why it is so shy.I even tried mussels and Octopus it nibbled at it and that was it.I was thinking of floating it in a basket till it got the smell of the other fish and it would be safe from getting attacked.Does any one have any suggestion who have kept them