Planet Yardrat is where Goku crash-landed after escaping the destruction of Planet Namek.
Planet Yardrat is the home world of the Yardrat race. After the battle with Frieza, Goku jumps into one of the Attack Balls the Ginyu Force left behind, mashes on the controls in a desperate attempt to get away, and ultimately crash-lands on Planet Yardrat. Some Yardrats find Goku and nurse him back to health. During his stay Goku is taught the Instant Transmission technique.