Hi shooting37, that is a fireworm. the fluffy white hair is'nt fluffy is really spikey and ti flare up when it is attack. If it touch it sting like burning sensation feeling which is why it called fireworm. It part of the brittleworm species. They 're hard to catch so ur lucky to get it. Eeryone has their own opinion about keeping them in the tank. I'm happy to get rid of mine as i find they're a pest and do more damage for what they are worth.