The Evil Prime Minister plots against the emperor's son in "The Mystery of the Four Dragons", a Season 3 Sesame Street insert that appears in Episode 0299.

In the story, an aged emperor in ancient Japan offers the throne to his son if he can find four dragons hidden in the room before midnight. The Evil Prime Minister thinks that the son will never find the dragons. The son finds the dragons in a painting, and inherits the empire. Occasionally, he would let out a sneering laugh that sounded like "Nyaaah-hah-hah-hah-hah-haaaah!"