Octopuses have eight arms (not tentacles), each of which has suckers from top to tip along its interior. Males have a specialized “hectocotylized” arm that they use to transfer sperm to the female while mating. 

Octopuses are cephalopods, members of the class Cephalopoda, which belongs to the phylum Mollusca. Its members are invertebrates that live in the ocean, have large heads, and have arms or tentacles.

An octopus’s funnel, which expels water, is at the end of its mantle, near its head, and can be moved 180 degrees to either side. It is used to propel the octopus through the water and to shoot water at something it dislikes. Research has also shown that octopuses use their funnel for play. In one study, octopuses were observed squirting empty pill bottles around in the water, either in a circle or back and forth across the surface.