What are some characteristics of an octopus?

* highly intelligent * relatively short life span * They have three hearts * They have eight arms * They do not have a internal skeleton * They can produce a thick blackish ink in a large cloud to aid in escaping from predators * When under attack, some octopuses can detach their own limbs * They move about by crawling or swimming
Changing colors is useful for self-defense because they become almost invisible to a predator.