S1·E3 The Nimbus Cloud of Roshi

As a token of appreciation, the Turtle Hermit presents Goku Kinto'un, a magical flying cloud that can be ridden only by someone pure of heart. He gives Bulma an orange bauble that he wears around his neck, a seemingly worthless stone that had washed up on the beach. It turns out that this "bauble" is in fact a Dragon Ball. Unfortunately for our friends, Pilaf and his aids, Mai and Shu, are also after this same Dragon Ball...and now they know that Bulma has it.