Bill Slank, otherwise known as Slank and William Slank, is a major antagonist featured in Peter and the Starcatcher and the book it is based off of, Peter and the Starcatchers.
Peter and the Starcatchers
In Peter and the Starcatchers, Slank is the first mate of the Never Land and one of the primary antagonists of the novel alongside Black Stache. He is one of the Others.
During Peter's stay on the Never Land, he notices that due to the severe incompetence of the captain, Slank is evidently the one who's truly in charge of the ship.
Peter and the Shadow Thieves
Slank reappears in Peter and the Shadow Thieves as a lesser antagonist, acting as one of Lord Ombra's subordinates so that the Others can once again get their hands on the starstuff.
Earlier in the novel, it is established that after the events of Peter and the Starcatchers, Slank grew starved at sea and was forced to kill and eat Little Richard before the former was rescued by Nerezza, a fellow agent of the Others.
The Broadway Play
Slank is a ruthless pirate who has been abandoned by his mother at a young age and is intent on getting his hands on a trunk containing magic dust, which Molly Aster, daughter of a lord, must protect.
He runs his ship, The Never Land, with an iron fist and forces the children enslaved on his desk to work against their will. One of the boys is the main protagonist.
Slank first displays his true evil when he captures Molly and locks her and her nanny, Mrs. Bumbrake, in the ship's hold. He owns a pet cat who is just as wicked as he is and he and his thugs set sail for Rundoon to get his treasure.
The evil pirate also displays his true nature when he tortures one of the sailors with a branding iron. He locks the boy, Peter, and his friends Teddy and Prentiss with Molly. The friends soon escape, but Slank ambushes Peter, grabs him up, and throws him overboard. Luckily, Molly saves Peter and when Slank comes across the wicked Black Stache, who is to become Captain Hook later in the play, they battle for the chest.
Soon, a storm rages, and when Slank makes a final attempt to grab the trunk, Mrs. Bumbrake throws his cat on his face, causing him to tumble over the side of the ship, where he winds up as shark food.