1-Shanks is the first character in the series to show any form of Haki. Oda recently revealed that Shanks has mastered to full extent all three types of Haki.
2-Shanks was first featured in the first pilot of One Piece Romance Dawn V.1 in the Shonen Jump specials showcasing upcoming artists, about a year and a half before One Piece began.
3-At the start of One Piece, Shanks bore a physical similarity to Luffy. As Oda’s style changed, Shanks became more distinct. The shape of his eyes are much sharper and narrower than they used to be. His nose has become more defined.
4-In the manga, when Shanks is floating in the sea holding Luffy after losing his arm, blood can be seen dripping from his missing arm. In the anime, this blood is missing.
5-So far, Shanks has only wielded a sword named Gryphon in combat. Gryphon is a large saber with a single edge blade and a large hand guard.
6-As the news of Luffy’s exploits at Totto Land spread across the world, Shanks read the newspaper and looked forward to seeing Luffy again.
He later went to Mary Geoise to speak with the Five Elders in person about a certain pirate.
7- Shanks is officially the Yonko with the Highest Bounty.
8-Shanks shares the same birthday as Dracule Mihawk and Franky.
9-Some real-life pirates were caught on video using Shanks’ Jolly Roger.
10-In the 6th Japanese Fan Poll, Shanks is ranked the 11th most popular character in One Piece, making him the most popular of the Yonko.