Hagfish, a.k.a slime eels are repulsive creatures.  They have slime glands on both sides of their body.  When a predator bites them or touches them, they release a protein that mixes with the salt water and expands.  This causes their attacker to choke, possibly to death.  Hagfish have been around before dinosaurs !  Meaning, they are one of the oldest creatures on earth!   That’s impressive for a nasty sea worm-like creature . If I saw one I’d try to take it and put into a plastic box full of water so I could examine it.  Thanks for taking time and reading my article.