Cnidarian

In Greek, the word "cnidos" means stinging nettle. The very diverse Cnidaria phylum contains thousands of species of animals. The have a structure in their stinging cells call a nematocyst. It resembles a spring-like coil . When the cnidarian stings its prey, the nematocyst uncoils and fires into the prey. Often, the sting contains some type of toxin that the cnidarian uses to stun or injure its prey. Most cnidarians are pretty much harmless to humans, though some are potentially deadly.

A jellyfish is one of the most recognized cnidarians. Jellyfish are often hunted by sea turtles, who may mistake plastic shopping bags like this one for a snack. If a turtle tries to eat this, it would probably choke to death. For this reason, it is important to ensure all garbage is disposed of properly, though, I'm sure the jellyfish wouldn't mind much.