Monkey D. Garp is an extremely famous and powerful Marine vice admiral. He is the father of Monkey D. Dragon, the paternal grandfather of Monkey D. Luffy, and the adoptive grandfather of Portgas D. Ace.
He took charge of both Koby and Helmeppo’s training. After the war, he became a Marine Instructor to train new recruits, though still retaining the rank of vice admiral. Notably, Garp was offered the rank of Admiral several times throughout his career, but he refused the offer of promotion every time.
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.
Due to his actions, he could be considered the main antagonist of the Post-Enies Lobby Arc. He is also a supporting antagonist in the Marineford Arc.
Garp is a tall, tanned, broad-chested, muscular old man. He has a beard and a scar over his left eye. In the anime, his eye color is blue, and his hair is gray, whereas in the manga, it is white. Garp and Tsuru are the only two vice admirals to have special shoulder-pads; Garp is golden and blue (black and red in the anime) while Tsuru is purple with white dot whereas the standard color is blue and red. During the Battle of Edd War, Garp’s had two black stripes on his epaulettes and during his appearance at Water 7, it increased to three stripes and by the time of the Marineford War, it increased again to four stripes.
The dog mask that Garp initially wore when introduced served to hide his identity as Luffy’s grandfather, whose design had appeared in Romance Dawn, Version 2. After their relationship was revealed in the Post-Enies Lobby Arc, Garp is no longer seen wearing the mask.