Adventures in Wonderland (1992)

S1E21 The Mirth of a Nation

Title: The Joyless Jubilee Plot: During her whimsical "Mirthday" celebration, the Queen accidentally hits her funny bone and loses her ability to laugh. In response, she enacts a decree forbidding laughter throughout Wonderland. The citizens, now somber and concerned, unite to devise a scheme to bring back joy and restore their beloved Queen's sense of humor.