50% Luke is a zombie pirate found near the mountains on Braindeath Island. As his name suggests, only half his body is flesh, the other is made of witchwood, which came from a now extinct tree. Players must sneak past him during the Rum Dealquest.
If a player wears an activated ring of Charos whilst talking to him, 50% Luke will reveal some of his history. In addition, if the player uses a tinderbox on 50% Luke, Luke will get angry and "hit a 500 hit combo" on the player.
When Luke fell overboard, he was thrown a rope by his crew, which he clung to as the ship continued on its course. When the ship passed over The Other 50% Reef, Luke was caught on the spiky coral, which mutilated the left side of his body. The reef was then given its name by The Inebriated's crew and is still labelled so on their maps today.
When the character asks 50% Luke for his story, Luke will say "Well, it all starts with an albatross...", this is a reference to the poem The Rime of the Ancient Mariner by the English poet Samuel Taylor Coleridge in which the main character of the poem kills an albatross and ends up cursing the crew and leaving them in an undead state, similar to the state Luke is in.
Pirates in fiction are often depicted with missing or substitute body parts (peg legs, hook-hands, eye patches, etc). 50% Luke is an extreme example of this, as he is missing 50% of his body.