I'm surprised nobody mentioned the spotted eel, it's very common. I think it's care is the same for tire track eels, and they reach a similar size I think. I've even heard from some where that they were just different color morphs. Mines maybe 14" long or so. Amazing fish, she has s favorite pile of rocks but likes to explore the driftwood sometimes. She eats a lot of night crawlers and some frozen blood worms. she eats the night crawlers right out of my hand. She likes to play a game where she pokes her head out of the rocks and check the worm out before swimming up to get the worm. She then dashes frantically into the rocks and disappears, only to poke her head out a few minutes later to see if there's another worm coming. Okay, that's probably just predator response, but it's cute.
BTW, i Refer to her as her because we named her Missy Eeliot.