[Disclaimer: I do Not Own One Piece That Honor Belongs to Oda. I'm only writing this for fun. (:
Walking through a jungle were an young boy of about five and an old man in his fifties.
"Hey Gramps where're we going huh" Luffy asked excitedly looking around and smiling when he saw some animals.
"Where are we going, WHERE ARE WE GOING YOU ASK, WE'RE GOING TO START YOUR TRAINING TO BE A GREAT MARINE!BWAHAHAHAHAHAHAHA!" Garp laughed like a maniac as he said this, berore grabbing Luffy and throwing him deeper in to the forest.
"AHHHhhhhhh" Luffy voice got fainter as he flew through the forest before putting his hand on his chin and wondering "I wonder if there is any meat in here?" Before his stomach let out a loud grumble "Ohhh" he moaned as he held his stomach, before he crashed into the ground "AHH" and bounced before crashing through some trees before finally coming to a stop on a boulder that cracked from the force. "Ohh that hurt." Luffy said as he got and looked around to get his bearings.
As he was about to walk off in search of food he heard growling "huh" before hearing it again except this time louder *GROWL* Turning around he froze. In front of him was the biggest tiger he had ever seen 25ft tall packed with muscle. "Wow that's a lot of meat" he said as his stomach growled even louder *GROWL* I'm sorry Mr. Tiger but I'm going to eat you." He said innocently as only a child can. Before jumping and punching the tiger as hard as he could right in the nose,*CRUNCH* *YOWL* the tiger screeched as it's nose broke, but before it could get it's bearings back Luffy pulled his fist back and put all his hunger all of his desire for meat into his punch, before letting it fly * BOOM* *Flash* and in a blue flash of light the tiger was down and Luffy was standing above it smiling happily at his accomplishment as he prepared to eat.
Three months had passed since Garp left Luffy in the jungle, and he had only remembered that day so he was rushing to see if his training had paid off. Running through the jungle knocking tree away left and right he wondered what Luffys's been up to "Probably sleeping in his underwear Bwahaha." As he laughed to himself he heard laughing up ahead. Peeking through some bushes he saw Luffy sitting on top of a mounten of giant animals he had defeated, laughing at the deafeated leader of the beasts. "Bwahahaha Luffy it's time to go." Garp said as he walked out of the bushes only to be met with the sight of Luffy about to punch him in the face, just as the fist was about to hit it flashed black and Garps eyes widened as he witnessed his almost six year old grandson use Armament Haki as he was punched in the face with all the strength Luffy had gained from his time in the jungle, it actually forced him back a step which was even more surprising. Just as he was going to get punched again he threw Luffy off him.
"Shishishishi hey gramps did you see how strong i've gotten huh huh did you did you?" Luffy asked excitedly as he bounced around, happy to see his Gramps again even if he left him in a jungle.
"Bwahaha yes I can see that I guess from now on I'm going to have to up your training." laughing as he said this but on the inside he wondered. 'Maybe I should start teaching him the Six Powers.' As he thought this he started to get excited at the prospect.
"Cmon Luffy it's time to start you new training bwahahaha!" He laughed excitedly as he picked Luffy up by the back of his head and ran back through the jungle with Luffy laughing along the way as well.