If I assume that your question is asking if the word “tentacles” relates only to the octopus or if tentacles could be used for other animals as well, then other people have already answered. read more
If, however, you were asking if the word “tentacles” was reserved for only species in the animal kingdom, as in octopuses, then no. The word tentacles is also used in the plant kingdom: From Wikipedia: In botany, tentacles are glandular hairs on the leaves of some species of insectivorous plants such as Drosera (sundews). read more
When most people hear the word "tentacle," the first animal they think of is probably a cephalopod. Cephalopods are a group of mollusks -- the same family as shellfish and snails -- that includes octopus, squid and cuttlefish. The family also includes the extinct belemite and ammonites. read more