BANG...What is this???

[browniebuck]

Bang...
Several people told me to ask you what this was...so, can you help???
https://forums.saltwaterfish.com/t/265934/what-is-this-thing#post_2080830
It is over 6 inches long (we haven't seen the whole thing, but I think that it is near a foot long total...or we have 2 of them), it has areas that seem to be blue, and it has bristles/spikes on the sides (not top or bottom).

 

[fedukeford]

Im no where close to as knowledgeable as bang guy, but it looks like a bristleworm too me.
Feduke

 

[bang guy]

Hard to tell any detail from the pictures but it looks like a beneficial Fireworm to me.
In my humble opinion it is good to have a couple large Fireworms in addition to a bunch of small Fireworms in a reef system. The population of the small worms will wax & wane based on the food supply and the larger worms will act as breeders to maintain the population in times of famine.