Monkey D. Garp

Vice-Admiral Monkey D. Garp (モンキー・D・ガープ中将 Monkī D. Gāpu Chūjō) is the commanding officer of the 153rd Branch of the Marines, and the man in charge of both Coby and Helmeppo. He is the father of Dragon D. Monkey and the grandfather of Luffy D. Monkey and Ace D. Portagas.

History
He frist appeared in the Coby/Helmeppo Mini-Story.

He is something of a father figure to the two of them, and helps keep their unorthodox behavior in check so that they can achieve their dreams of greatness in the Marines. Garp also displays a fondness for eating doughnuts, as well as a tendency to fall asleep at inappropriate moments.

Trivia
Garp's design is based on Luffy's grandpa from Romance Dawn Verison 2, both in appearance and his apparent habbit of beating people during disagreements (as Koby and Helmeppo found out when he over heard Helmeppo talking about him). Ace apparently gets his habbit of falling asleep randomly from his grandfather.

Oda scrapped Luffy's grandfather from the main storyline in 1997 but may had already decided that Luffy's grandfather should be an marine and did not introduce Garp until 1999 so because Garp is recycled from Romance Dawn's grandfather, it's safe to say that Garp was the 1997 character but was not materized until 1999.