A few months ago, I picked up a 6" Humu from work. All other specimens I'd seen, they were all laid back, very peaceful, etc. This one, however, would attack the Mag-Float and anything else you put in the tank. Reluctantly, I went ahead and brought him home but placed him in my 150gal. Rubbermaid for quarentine.
I had him for over a month and every time I started to put him in the display, I just couldnt bring myself to do it. I have my Hawaiian Dragon Moray and was just nervous about the Humu attacking her.
I took it back to the store, but we were out of room if I wanted to put it into a tank by itself. I placed it in a tank with a 8" - 10" Giant Hawkfish, thinking everything would be ok. Less than 20 seconds in the tank, the Humu went directly for the Hawkfish's eyes...just trying to destroy this poor Hawkfish.
Thankfully, I got the Humu out, before it did any damage. The Humu is still at the store and since then, I've brought the Giant Hawkfish home and he now resides with the Hawaiian Dragon and Whitemouth Moray.
I once had a 1.5" - 2" Humu kill and eat a 7" Peacock Mantis Shrimp. Talk about being surprised...