Master Roshi

Master Roshi (武天老師, Muten Rōshi), also known as the Turtle Hermit (亀仙人, Kamesen'nin), is an ancient and wise martial arts master and the first character to wield the trademark Kamehameha. Though he seems frail, he is a mighty warrior. Master Roshi trained Grandpa Gohan, Ox-King, Goku, Krillin, and Yamcha. His home, named Kame House, is a shack on a small isolated island, and serves as a gathering place for "his friends". He is both the archetypal wise old man and a perverted old man, the latter being typical of shōnen manga. Sometimes, he gets cranky, which further provides comic relief. He is bald, with a thick fu manchu, and a thick beard. Master Roshi wears beach clothes or a martial arts suit and a Turtle Shell on his back. He usually wields a walking stick. His companions are usually Oolong, Turtle, and Launch.

Master Roshi is over three hundred years old at the start of the series, and provides various stories to explain his longevity. Roshi enjoys eating home delivered pizza, according to Toriyama, which serves as a tongue-in-cheek joke because Roshi lives so far out into the ocean. He is a very lecherous pervert, and is constantly watching Aerobics Women on television or looking at Dirty Magazines in his spare time. He even accepts a bribe from Bulma, to show him her panties in exchange for a Dragon Ball early in the series (and got a very big surprise, as Bulma unknowingly was not wearing any panties when she exposed herself). Master Roshi constantly tries to molest any remotely sexy woman he can get close enough to; usually Bulma or Launch in Dragon Ball or Maron in Dragon Ball Z. He firmly believes that he is the ultimate stud and very, very cool, even though his fashion sense and mannerisms seem to be at least a few generations out of style. Although he is dedicated to training his students in the way of the Turtle clan, he will nonetheless tell off his students when they are practicing the Kamehameha wave because the water is ruining his magazines. The only time he did not tell off one of his students for this when practicing the Kamehameha wave was when Krillin tried to practice it in order to get his mind off his breakup with Maron, partially because he was asleep when it happened.
Despite his skirt-chasing antics, Master Roshi is still a very wise and kind-hearted person who loves those around him like his own grandchildren. He openly enjoys life and its simple pleasures, but is willing to die for an honorable cause if necessary. Despite being noted by Turtle in the chapter "Kame-sennin's Basho-sen" that Master Roshi has consumed the "immortality elixir", Roshi dies when attempting to utilize the Evil Containment Wave against King Piccolo (who was freed during the King Piccolo Saga), which shows that the elixir grants immortality, but not invulnerability. He appears in most of the Dragon Ball and Dragon Ball Z movies, usually as comic relief in the films. After the fight against Majin Buu, Master Roshi left his old sunglasses, and went to more futuristic ones.

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