Cephalopods have the most well developed nervous systems of all mollusks, as well as the most well developed eye. The cephalopod eye is one of the most notable examples of convergent evolution in all of the animal world, because this eye evolved from a completely different direction than the mammalian eye, yet it turned out to function in almost the exact same way. Cephalopods, therefore, have extremely good eyesight. This eyesight is well suited for finding prey. The cephalopod then grasps the prey firmly with its arms and eats the prey with a mouth located between the arms.
Cephalopods also have a beak, very similar to that of a parrot, used to help bite into prey.
The Blue-Ringed octopus of the South Pacific has a salivary gland which secretes a venom to subdue prey. The venom is so powerful that the bite of this octopus is almost always lethal to a human. The Common Caribbean octopus on the prowl at night, looking for food. While the octopus has eight sucker-equipped arms, the squid actually has ten. Eight of the squid arms are of the same length, while the other two are extra long, and are used for helping to grab prey.