Jellyfish

Jellyfish is a primarily blue creature type used for cards depicting transparent free-swimming (or flying) bell-shaped creatures with tentacles and stingers. Note that jellyfish, which are invertebrates and don't have gills, are not fish.

The first creature to bear the type was Man-o'-War in Visions, though Avizoa from Weatherlight was later issued errata to become Jellyfish as well. While the flying Avizoa hail from Dominaria, the similar Esperzoa and Gomazoa are from Alara and Zendikar, respectively.

Trivia

 * Man-o'-War is the only real, lifelike Jellyfish.
 * The subtype Avizoa was changed to Jellyfish in the Weatherlight online release.
 * In the Grand Creature Type Update the subtype of Glowing Anemone was changed from Beast to Anemone. However, it was quickly realized that an anemone is actually a terrestrial flower. Sea anemones on the other hand are the concerned water-dwelling, predatory animals. Since sea anemones are closely related to jellyfish, the subtype was changed accordingly in the update of the Grand Update.