"It's a Most Unusual Day" is a song celebrating the exuberance of life. It has been covered by such artists as Andy Williams and used ironically by Alfred Hitchcock in North by Northwest.

Robbie and Earl Sinclair performed it on the Dinosaurs episode "A New Leaf," gleefully uninhibited by their ingestion of "the happy plant." They perform a complex dance, choreographed by suit performers Bill Barretta and Leif Tilden.