Fiesta Fiasco is a 1967 Warner Bros.-Seven Arts Looney Tunes theatrical cartoon starring Speedy Gonzales, Daffy Duck and other mice. This cartoon short is directed by Alex Lovy and written by Cal Howard.
Speedy Gonzales and his friends set up balloons and streamers for a fiesta. When they learn that Daffy Duck is approaching, they cease preparing and hide. When Daffy asks about the decorations, Speedy says that he does not see anything.
Daffy decides that the mice have planned a party and have chosen not to invite him. He then sets out on ruining their party. He builds a machine that creates a raincloud. Instead of raining on the mice, the cloud follows Daffy and causes him lots of problems. He is struck by lightning, he is caught up in a tornado and he is constantly rained upon (it's possible the raincloud had a will of its own and didn't want Daffy to ruin the preparations).
After suffering much torture from the raincloud, Daffy learns that the fiesta is really his surprise birthday party. (In reality, 1967 marked the 30th anniversary of Daffy's debut.)