1-Blackbeard’s epithet and first name comes from the infamous Edward Teach, the real-life Blackbeard. Oda once stated that Blackbeard was his favorite historical pirate. Edward Teach is not only the namesake of Blackbeard, but also of the character’s former captain Edward Newgate and his crewmate and victim Thatch, as Edward Teach was also referred to as Edward Thatch.
2-After the time skip, Teach has grown a long beard that he has split into multiple sections, very much like his real life basis.
3-One Piece Green: Secret Pieces revealed an early concept of Blackbeard. He was originally named Everything D. Teach. This name may come from 17th-century English pirate Henry Every, famous for becoming the richest pirate in the world at the time and getting the highest bounty in history placed on his head.
4-Teach is the only known person to serve as both a Shichibukai and later a Yonko.
He’s also the only known Yonko to once serve under another Yonko’s crew. He joined the Whitebeard Pirates at the age of 12.
5-Teach currently has the lowest bounty among the Yonko. During the timeskip, he has gained mass notoriety with his bounty being 2,247,600,000 Berries, showing how dangerous he has become.
He’s the new power that replaced Whitebeard, and he’s still growing.
Marshall D. Teach holds the record for the highest numeric value of bounty increases total (raised from 0 Berries to 2,247,600,000 Berries).
6- Teach is the only person in history known to have the powers of two Devil Fruits. Through unknown means, he acquired the extremely destructive powers of the Gura Gura no Mi from the dead body of Whitebeard.
7-In Chapter 581, when addressing the prisoners of Level 6 of Impel Down, he is shown with a full mouth of teeth. This was likely a mistake on Oda’s part.
8-In SBS Volume 63, Oda drew the Shichibukai as children. Teach is shown wearing a baseball cap with a rolled up long sleeve shirt and green shorts. He is also wearing black curled tip shoes, and unlike his usual cheerful expression, is crying for an unknown reason.
9-Teach’s birthday, August 3rd, comes from his Devil Fruit’s name since 8-3 can be derived from ya-mi.
10-In the 6th fan poll, Teach ranked 49th.
