Do you know how many tentacles an octopus has? Many people might be surprised to learn that the correct answer is "zero" since octopuses have no tentacle at all. Instead, they have "arms," eight arms - or six "arms" and two "legs," to be precise.
Octopuses possess eight appendages, each of which has rows of suckers along its length. So, in strict anatomical terms, these are not called "tentacles" but arms - since tentacles have suckers only on their pad-shaped ending.
Examples of invertebrates with tentacles include squid, cuttlefish, bryozoa, snails, sea anemones, and jellyfish. Examples of vertebrates with tentacles include caecilians and star-nosed moles. Interestingly, squid and cuttlefish have both: arms and tentacles.
Picture: Octopus using both a nutshell and a clamshell as shelter (Wikipedia)