From Monkey Island wiki
The Death Starfish was LeChuck's ship in The Curse of Monkey Island. Its name is likely a pun on the Death Star from the Star Wars series. The ship itself was used by LeChuck as the forefront for his forces and his legions of undead soldiers to lead brutal attacks on fleets of ships, settlements, and islands, eventually staging an attack against Plunder Island as part of LeChuck's plans to conquer the island and abduct Elaine Marley, governor of the island and the entire Tri-Island area. The ship is shown to have destroyed all the defensive ships around the island with ease and proceeds to devastate the fortress, leading to the deaths of hundreds of individuals. Additionally, LeChuck uses the ship to horde all his recently plundered treasure and ill gotten gains in order to impress Elaine and bribe her love in order to entice her to marry him.
LeChuck dispatches rowboats filled with dozens of his followers to serve as an invasion force while he plans to create and use a Voodoo Cannonball to blow down the walls of the fort to allow his crew to overrun the island and reanimate Elaine into a demon, leaving her easily susceptible to LeChuck's control. However, Guybrush Threepwood shows up literally in the middle of the great battle after escaping from LeChuck's Carnival of the Damned on a bumper car and is captured by LeChuck and thrown into the hold to be dealt with after the battle is won. Unfortunately for LeChuck, Guybrush is able to gain control of the cannon within the hold and destroys the invasion force and then escapes by cutting the restraining rope on the cannon and firing it, causing the entire weapon to ram through the hold's door.
As a result, LeChuck drops the recently completed Voodoo Cannonball, blowing himself up and capsizing his ship. After Guybrush escapes from the wreckage of the ship, it sinks to the ocean floor, taking all of LeChuck's followers and riches with it. The battle itself served as a pivotal event within the series as the effects of the Voodoo Cannonball reanimated LeChuck into a demon pirate while Guybrush found a cursed voodoo ring in LeChuck's hold, which he used to propose to Elaine, not knowing it would turn her into a solid gold statue; the basis of the rest of the story chronicling Guybrush's attempts to lift the curse with a pure ring of equal or greater value.
Besides a hand-held cannon that LeChuck uses to fire at the water near the ship, many cannons can be found below decks, firing at the fort on Plunder Island. There is also a room full of treasures guarded by a locked door with no apparent doorknob, which contains a cursed diamond ring and a bag of wooden nickels, among other treasures.
There was also apparently a door which contained, when looking through the keyhole, children from all over the world holding hands and singing about world peace. Unfortunately, Guybrush says, it's really too dark to clearly make anything out. This is a reference to Disneyland's ride 'It's a small, small world'.
During a raid on the fort on Plunder Island, the Death Starfish sinks after LeChuck drops the Voodoo Cannonball. Before that happens, however, the ship seems indestructible, as the cannonballs from Elaine's fort couldn't do any damage to it.
- The Curse of Monkey Island (though its name is never said)