Much like Deku Shrubs, Octorocks will shoot projectiles at Link. In the 2D games, Octorocks lived on land and need only be hit by a sword to meet their end. In 3D games however, they are shown to be the Deku shrubs of the sea, shooting projectiles and disappearing if link gets to close.
Big Octo, is a reoccurring miniboss of the 3D games.
A Octorok is in a glass capsule in the Lakebed Lab.