That's a Fimbriated and no, they dont get very big...max out around 32".
They will, however, kill anything and everything in your tank...fish, inverts, other eels...you name it, it'll end up dead.
If you choose to get it, you should keep it in a tank byitself, unless you consider the other fish expendable. Feed a big variety of very meaty fish...grouper, salmon, squid, octo, etc.