He is a gray octopus-resembling alien bearing two long tentacles for each of his arms and legs. He served as the helmsman to Captain Amelia, though he may have maintained his position as such during the mutiny. He is 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.
- He is Silver's 1st Mate.
- In the sound book, Turnbuckle is next to Scroop.
- In the images of Treasure Planet, he is shooting the ships longboat room with Hands, Crex, Mertock, Longbourne, Fayvoon and Scroop.
- oddly Turnbuckle is featured in the PC game Treasure Planet: Battle at Procyon even though he had died.