those fish are very aggresive and kill basically anything else in the tank (or lake, river,..you get it)
i asked about them at the pet store before and i heard they are illegal because they can adapt to water very easy and eat basically anything...
they can also breathe out of water for a little while...
that would be pretty creepy if it got out while you were sleeping if you ask me! ha
but overall i think those fish are pretty awesome..
I have two red snakeheads (Channa Micropeltes) at the moment. When they were smaller it was possible to keep them with other large fish like pacu's and pleco's. But now they are app. 60 cm and will eat and attack everything in the tank even when they aren't hungry.
You can see my gallery for pics of my two snakeheads.