This unnamed species of jellyfish-like creatures appear in Samurai Jack episode, "XCV".
Overview[]
They are described as multi-green colored cnidarians with a bubble shape top heads, rows of antennas or eyes below their body and possess long tentacles. These creatures can also blew themselves up into puffs of smoke.
During in the episode, where both Jack and Ashi, who being carried on his back, jumped on a dozen of them while trying to escape from the inside of another creature through its blowhole. When they all soon began to shake and then explode which allows the samurai to escape. It is unknown if wheather or not this species would still exist without Aku's tyranny.