Cotton was a pirate who operated in the Caribbean during the Age of Piracy, most notably during the mid-18th century. Little is known about his early life. Prior to joining the crew of the Black Pearl, Cotton had his tongue cut out, due to an encounter with Mungard. He subsequently trained his loyal parrot to speak for him -- though how he achieved such a feat, as a mute, remains unknown. It's unknown what happened to him since Pirates of the Caribbean: At World's End but his parrot can be seen in the bottle where the Black Pearl was trapped at Pirates of the Caribbean: On Stranger Tides.
Cotton shows what Mungard did to his tongue.
"Wind in the sails."
Cotton watches Leech and his would-be mutineers fall to their doom.
Cotton speaks in the short film, Tales of the Code: Wedlocked. This short shows part of an encounter he has with Mungard, played by Christopher Rocha, in which Mungard shoots the pirate code when trying to shoot the Auctioneer and says he'll have the tongue of anyone who mentions him doing so. Cotton says "Mum's the word", but it can be inferred that he spoke about it and that is how he lost his tongue.