Octo

Octo, originally known as Scowler or the Squid, is a big squid that first appeared as one of the bosses in Wario Land 3.

Wario Land 3
In Wario Land 3, Scowler is the boss found in Sea Turtle Rocks. His main attack is to try to grab Wario with his tentacle. If he does, Wario will be thrown out of the cave and on the surface at the left side in the main area. Initially, Scowler's weak spot is its head, and mainly moves all the way horizontally, and then move vertically after it is all the way left or right. Occasionally, it will shoot out ink, which if it hits Wario, cause the screen to temporarily darken except for its face and Wario's location. After touching the glowing bump on its head, it will retract the bump and then expose a glowing underside while moving diagonally and ricocheting across the water. In this state, Wario must go underneath it to touch the glowing bump to hit it, causing it reverts back to its previous state. After three such hits, Scowler will be defeated and then a floating ring will float up, which will move up if Wario steps on it to be able to reach a platform that leads to the Gray Chest, containing the third of the five music boxes.

Dr. Mario 64
Scowler, now renamed Octo, reappears in Dr. Mario 64 as one of the enemies Dr. Mario or Wario have to face.

Unlike in his original appearance, Octo's body is colored orange rather than black in the American release of the game. In the later port of the game released in Japan as part of Nintendo Puzzle Collection, he retains his original black color scheme. His appearance may have been changed in Dr. Mario 64 due to a possible resemblance to blackface actors, similar to another situation faced by Nintendo with one of its Pokémon, Jynx.

Trivia

 * On the back cover of Chinese version for Dr. Mario 64, Octo, along with Spearhead, Appleby and Hammer-Bot, were referred as Mad Scienstein's minions.