Dragon Ball Z - episode 70 - 04 Dec, 1990

Goku is obviously more powerful than Ginyu, but the Captain won't give up so easily. Meanwhile, Guru sends Dende to tell Krillin and Gohan the password to use the Dragon Balls. Frieza arrives at Guru's place, demanding to know the Dragon Balls' password. The last three Namekians arrive as well. But despite Nail's pleas, they about to fight Frieza, but the tyrant easily kills them. Though Nail informs him that the Dragon Balls would disappear, following Guru's death, Frieza confronts Guru to get the password anyway. (Source: Wikipedia)