If you don’t like the idea of 10-foot long aquatic killer worms, then read no further.
The worms in question are called Bobbit worms, iridescent, and quite pretty. So far, all fine and dandy. But these aquatic worms, while on average about 3 feet long, can grow to 10 feet, and have a nasty habit of lurking in a hole, waiting to lash out and grab any passing unwary fish in jaws that can snap a fish in two.
As for their reproductive habits, little is known, but if they’re similar to related worms, well, best you read this Wired article. All I’ll say is that the Bobbit worm joins this creature in reminding me of this song (NSFW).
H/t to Smut Clyde for bringing this creature to my attention, and providing a mental image difficult to erase (Smut’s blog, Riddled, contains more invertebrate nightmares than you ever wish to encounter).
Update: thanks again to Smut Clyde, here is some information about How The Bobbit Worm Got Its Name. Enjoy!