Octopus and snail are related, but octopus is not protected by hard shell. Octopus's body is elastic and can squeeze into tiny caves. All octopuses are carnivores, mainly feeding on animals such as crabs. The beak of a bird can bite through the crab shell and spray out toxins that can paralyze the nerves. Octopus is a mollusk with eight legs or tentacles. Among mollusks, octopus and squid are the most evolved group. They use tentacles and suckers to ingest food. Sensitive tentacles can send food such as small fish, shrimp and crabs into its mouth. Octopus has 24 suckers on its wrist. They cling to the bottom of the sea by these rows of suckers and crawl at will, touching objects to catch food. There is a circle of sharp teeth around the sucker, which is very convenient for catching prey.