A real sea monster!!

We're moving. We have a salt water aquarium. We had a few fish, once upon a time, but none for ages. We've kept the aquarium in nice condition but without the fish some algae has grown and since we're moving we decided to clean it out well and get it ready for storage. I took out the faux-coral pieces and cleaned them nicely. Amazing what a scrubby brush can do! The yellow and pink corals are once again, yellow and pink and not brownish-red and green! Algae is pretty fast growing and it takes over any space it wants. Without fish, that growing process is even faster since there's no one to dine on it.
I cleaned off the faux-corals and got them put away. I was about to grab one of the pieces of live-rock (this is coral that you can get from the petstore that has been grown for aquariums but has died so it's great hiding for your fish and it has beneficial bacteria on it, yadda yadda yadda...) I just happened to glance on the side of this piece of live-rock and I see a pink tentacle-type thing poking through one of the holes. OMG... WTF?! We have had this live-rock crap for 2 years. We have only EVER HAD FISH in this aquarium. One clown fish, a lawnmower blenny and a blue tang (think "Finding Nemo"). NEVER EVER have we purchased ANYTHING even REMOTELY PINK and tentacly!!!
I took a deep breath and called my hubby to come take a look. At 1st he thought it was a spine from a fish who met his demise. Our clownfish just vanished one day, and we never saw it again. He thought it may have gotten stuck on the side of this piece of live rock. BUT.. that was MONTHS ago! Surely he would have decomposed?? (Ok totally GROSS, right??) Well.. it ISN'T a 'clownfish spine'! We watched it for a few minutes as it emerged from it's live-rock condominium. It was about 3.5 inches long, looked like an earthworm with white bristles on it's sides. I ran over to the computer and typed in "Sea Worm" (that was the ONLY THING I could think of!!!) A list of sites with 'SEA WORM' as their subject headings come up. I clicked. Then I wish I hadn't clicked. I was introduced to our "Bristle Worm"

So now you have been introduced to our sea monster too. Aren't you glad I shared???