Thatch

Thatch was the commander of the 4th Division of the Whitebeard Pirates.

It was revealed that, Thatch found the Devil Fruit that Blackbeard was after (the Yami Yami no Mi). This Devil Fruit was the very reason that Blackbeard joined the Whitebeard Pirates, so he killed Thatch and ran off with it.

Trivia

 * Seeing a resemblance between Thatch's name and that of the alias of the real life Blackbeard, Edward Thatch, a fan asked Oda, in a SBS question, if Thatch was based on the real life Blackbeard along with Edward Newgate and Marshall D. Teach. Oda replied to the fan that he indeed based Thatch's name on the real life Blackbeard's alias however the basis is in name only.