The Batik Loach
Again, bad fish owner for not doing research before hand. The description on loaches.com includes "This is a rather shy and secretive loach that likes to come into full light only while feeding, and likes to live singly. It prefers small pebbles or sand to burrow in."
It forgot to mention that it comes with its own improbability drive, similar to that of the Heart of Gold. I expect tomorrow morning it will have a Bermuda shirt on from its travels today. The shirt will be underneath his ninja costume, of course.