Some facts about Octopi include

Origin of the word Octopus

• The word Octopus comes from the greek word októpus meaning "eight foot"

Body Facts about Octopi

• Octopi have not 1 but 3 hearts, one pumps blood through its organs, and the other two pump blood through its gills
• Octopus blood is blue because it has a copper based protein called hemocyanin

Size of Octopus

• The everday/common Octopus is 12 to 36 inches long and weighs 6.6 to 22 lbs

Habitat

• Octopi live in oceans all around the world. Most are pelagic, meaning they live near the water's surface in shells, reefs, and some small crevices
• Some species live on the floor of the ocean, making their homes out of caves.

Source: livescience.com