The Ox King on Fire Mountain (S01E07)

Upon reaching Mt. Frypan, Goku and his friends find themselves in a tight spot when Gyumao, the castle guardian, spots them. However, Gyumao's demeanor shifts dramatically once he learns that they are acquainted with Muten Roshi. To put out the flames of Mt. Frypan, he asks Goku to team up with his daughter Chi-Chi to retrieve Muten Roshi's Basho Fan. Goku meets Chi-Chi, who is able to ride on Kinto'un, but his energy falters when she grabs his tail! Witnessing this, Yamcha realizes Goku’s vulnerability!