Yajirobe

Yajirobe (ヤジロベー Yajirobē?) is an overweight samurai that Goku meets in Dragon Ball. He is often considered to be rude, unmannered, timid, lazy, and cowardly. During their first meeting, Yajirobe gets mad at Goku for stealing his fish, and hates him. However, he has a change of heart, and helps Goku prepare for the battle against Piccolo Daimao, and continues to support Goku and his companions, though often from the sidelines. He trains under Kami with the others in order to prepare for the Saiyans, and helps in their victory by cutting off Vegeta's tail. During Dragon Ball, he is a wanderer that lives off the land, but after meeting Korin and discovering the Senzu Beans, which provide the nutrients of ten days worth of meals, restore energy and heal wounds, he decides to live with Korin. He begins growing the beans with him, and often delivers them to Goku and his companions. He plays a part in Goku's first fight in Vegeta when Vegeta stares at a full moon and transforms into an ape monster. Yajirobe takes his sword and cuts off his tail. However, when Vegeta becomes enraged and threatens Yajirobe with death, he backs off and tells Vegeta that he wants to be on his team. His cowardly actions are shown again when he runs away from the Androids.

Information from:
http://dragonball.wikia.com/