 FACT: Although the title of the film is "Tentacoli" ("Tentacles"),  and it is about a murderous giant octopus, octopuses do not have  tentacles, they have arms. Scientifically, the definition of  "tentacle" is commonly accepted as an elongated structure with  suckers at the very tip. A squid normally has two tentacles, along  with many arms, but octopuses do not have tentacles.