|“||Aye, Captain. 2-1-0-0.||„|
Turnbuckle is a gray octopus-resembling alien bearing slug-like eyes and two long tentacles for each of his arms and legs.
Turnbuckle serves as the helmsman to Captain Amelia, though he may have maintained his position as such during the mutiny. During the voyage, the ship encounters a supernova. While securing lifelines of all pirates so that they will not get lost, Jim saves Silver from falling just in time. The supernova then devolves into a black hole, where Arrow falls to his death. The burst of shock waves and maximum engine power enable Amelia to pilot the ship to safety. Amelia mourns the loss of Arrow, and suspects Jim of failing to secure the lifelines, while Arrow's line was actually cut by the most dangerous insectoid alien named Scroop. Meanwhile, Turnbuckle and the pirates corner the group here; using a back door, Jim, B.E.N., and Morph return to the ship in an attempt to recover the map. He is also one of the last two pirates (the other being Blinko) to die in the film; during the collapse of Treasure Planet, as he and Blinko instantaneously struggled to escape with their ill-gotten gains, they were caught in the waterfall of gold coins and fell into the lava-filled crevices to their deaths.
- "Aye, Captain. 2-1-0-0."
- "Aye, Captain."
- "We're being pulled in! Ohh!"
- "Poor boy." (his last words)
- Turnbuckle's voice actor in the movie, Rodger Bumpass is the same actor who also voiced Squidward Tentacles in the SpongeBob SquarePants franchise.
- In Treasure Planet: Battle at Procyon, a continuity error is made as in the game, he is still alive and tells Jim "beware" while handing him a piece of dark matter, but in the movie, he falls to his death with Blinko at the planet's exploding core.
- In the book Treasure Planet: A Voyage of Discovery, it's mentioned that Turnbuckle has known John Silver and Scroop long before the film's events, serving as Silver's right-hand, but that their dynamic changes once Silver starts looking after Jim.