Giant Monkey Robot
From Monkey Island wiki
The Giant Monkey Robot is an enormous contraption hidden on Monkey Island that serves as an important mode of transportation and weapon in the finale of Escape from Monkey Island.
Initially only its head, the well-known Giant Monkey Head, is visible above ground, but when the Caverns of Meat beneath Monkey island are sealed up between the events of the third and fourth games, the control room of the robot becomes accessible. The entrance is revealed by activating a switch in the robot's nostril. Guybrush Threepwood, Jojo Jr. and H.T. Marley use the robot to escape from Monkey Island and destroy the tower built by Ozzie Mandrill to amplify the power of the Ultimate Insult and use it on every pirate in the Tri-Island Area; they accomplished this simply by hitting an off switch on the tower. After that the robot was used to battle Ozzie and LeChuck in a final Ultimate Monkey Kombat.
The Monkey Robot became activated when Guybrush used the Giant Monkey Head to create a gigantic Ultimate Insult talisman (using Herman's golden Banana Picker and Jojo Jr.'s Bronze Hat). After placing the Gubernatorial Seal of Mêlée Island (the secret fourth piece of the Insult) into a slot in the control room, the Monkey Head began to emanate a green light which drew the monkeys of Monkey Island to it.
The robot is steam-powered (the heat for which is generated by the flow of lava from Monkey Island's volcano) and controlled primarily from the command room. There are also several smaller control units operated by monkeys which presumably move the robot's limbs.
Despite its steam-powered nature and clunky appearance the robot is perfectly capable of preforming Monkey Kombat stances. In Monkey Kombat it is invincible because its health bar automatically restores itself whenever it's hit.
After the climatic battle Jojo and the other monkeys embark for parts unknown on board the robot monkey.
