What On Earth Is This Bizarre Creature, And What Is It Shooting?

This strange creature was found by a Taiwanese fisherman. It was later identified as a nemertean, or ribbon worm, of the species Lineus fuscoviridis. They can be found in the waters between Japan and The Philippines, and can grow to a massive 2 meters in length.

Check out the footage of this underwater oddity below:

^{Credit: YouTube/簡偉丞 via Storyful}