My cousin has kept gills, cats, crappie, etc. in a tank before. It's actually really cool watching their behaviors, the ways they eat, etc... Kind of cool.

Here's a funny story he told me as well... He caught a 6 or 7 pound flathead cat several years ago and put it in his biggest tank. He and his wife had fish tanks, cats, dogs, birds, and other critters. One of their pet birds was a talking parrot.

He said he was roused out of a deep sleep one night because the parrot was squauking and going nuts. It was 2 or 3 in the morning and he started down the stairs expecting to come face to face with an intruder. He said the parrot was carrying on and out of sorts because the flathead had jumped out of the tank and was flopping all over their living room. When I asked him what he did with the flathead he said, "I got dressed, went outside and filleted him."