A giant Pacific octopus--the largest of the world's 250 or so octopus species--can easily overpower a person. Just one of a big male's three-inch-diameter suckers can lift 30 pounds, and a giant Pacific octopus has 1,600 of them. An octopus bite can inject a neurotoxic venom as well as saliva that has the ability to dissolve flesh. Worst of all, an octopus can take the opportunity to escape from an open tank, and an escaped octopus is a big problem for both the octopus and the aquarium.