#1- Garp is one of the major figures, along with Kong, Sengoku, Shiki, Silvers Rayleigh, and Whitebeard, from the times when the “Pirate King” was still alive.
#2- 38 years ago, he earned his epithet “Hero of the Marines” during the time known as the “Era of Rocks” by defeating Rocks D. Xebec in God Valley, through joint forces with Gol D. Roger. However Garp rarely discusses the God Valley Incident as he feels shame about this event.
#3- Garp was offered a promotion to admiral position many times from Fleet Admiral Kong, but he declined every time. The main reason was because he refused to work under authority of the Celestial Dragons.
#4- Garp is one of the very few people in the world who can use all three types of Haki. He is also a capable teacher, as he taught Kuzan, Koby and Helmeppo.
#5- Aside from Luffy himself, Garp is the only Romance Dawn V.2 character to actually appear in the storyline.
Some aspects of his character remain from Romance Dawn version 2. He is as hot tempered as ever and intolerable to Luffy’s antics. Like the final version, he was determined to make Luffy follow in his footsteps, however here he is a pirate captain, a complete opposite of his current occupation. Both stories have in return Luffy completely rejecting the idea of following in his grandfather’s footsteps.
#6- In One Piece Magazine Vol.5, Oda drew a “what-if” illustration of Ace, Luffy, and Sabo as Marines. Garp was seen wielding a pair of katana swords.
#7- When he was a child and a young Marine, Garp resembled Luffy, though more muscular than his grandson. As a child, he wore a tropical button shirt with shorts and wielded a pipe staff. Garp already had the scar on his left eye in his childhood days.
#8- Oda drew Luffy’s possible appearances in his adulthood in two different timelines, at ages 40 and 60. Given how Garp resembled Luffy as a kid, it’s fitting that Luffy would resemble Garp as an old man.
#9- Garp shares some similarities with Smoker:
Both of them are Marine Vice Admirals.
Both of them have white hair.
Both of them are from East Blue.
Both cornered many times a certain pirate they were chasing (Roger for Garp and Luffy for Smoker).
Both of them are often accompanied by a swordsman (Bogard for Garp and Tashigi for Smoker).
Both of them have a scar on their face next to one eye.
#10- Due to his grudge against him, Chinjao wants Garp to suffer the pain of losing someone close to him. Ironically, Garp already underwent that pain upon losing Ace.