Dragon Ball Z - episode 60 - 04 Sep, 1990

Bulma finally retrieves the Dragon Ball, only to be captured by two of Frieza's henchmen. She persuades them into find the rest of the Dragon Balls and making a wish themselves. Knowing she has more Dragon Ball knowledge than the two of them, they take her along. She leads them into the water, and right to the giant crab, who eats both of them. (Source: Wikipedia)