Unnamed Garp was introduced in Romance Dawn V.2 (featured in Weekly Shonen Jump magazine itself) as Luffy’s grandfather. For a long time, it was first thought that Luffy’s unnamed Grandfather was a sole addition to Romance Dawn V.2.
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. Garp now adorns a dog hat and compared to his chubby Romance Dawn V.2 version, his upper body is much more muscular.
One feature carried over from Luffy’s grandfather from V.2 to the final version of Garp was the scar on his left eye. Also, Luffy got both his hat and the Devil fruit he ate from his grandfather in V.2, not Shanks. According to Oda the reason for not featuring Shanks was that he wanted Shanks to be kept a secret until One Piece was serialized so he would have a greater impact.