The Goodwill Ambassador
From the Super Mario Wiki
The Goodwill Ambassador is a character found in the Game Boy Advance game Mario & Luigi: Superstar Saga, released in 2003. The ambassador, who is actually Cackletta disguised as Lady Lima, appears only in the opening cut-scene of the game where she and her accomplice, Fawful, visit the Mushroom Kingdom. It is later revealed that Prince Peasley of the Beanbean Kingdom knew beforehand what Cackletta had planned, so he warns the princess. Peach and Toadsworth then organize an an imposter to take her place when the ambassadors arrive.