my hippo tang had a really rough early life with the crash of my 425L, an emergency run in a bucket to the LFS for 2 weeks, back to my hospital tank, then into my back up nano tank, back into the hospital tank, back into my nano, then finally into her current M100 home. But she was a very small juvenile when I got her so she fit into those small emergency quarters. the downside was she would ONLY eat pellets for the longest time. Once I introduced other fish (my big ones being the foxface and the sailfin) suddenly she became more social and started taking to the random algae growing on the back wall of the tank, and even watches the foxface and sailfin eating nori strips. But the hippo really cracks me up, if she's by her self, she would just hide and waste away, if there are other fish she's very social and wants to see what everyone else is doing.
The Chromis think she's pretty cool and follow her whenever they can.