That's All Folks is the closing title card on almost every Looney Tunes story. It was first used by Bosko and more commonly by Porky Pig in the Golden Age of Animation, before the standard script logo on the bullseye came to use. It had many variations over the years, depending on the situation, which is similar to the Couch Gag opening of The Simpsons.
Bosko was the first character to say the phrase starting with the first official Looney Tune, Sinkin' In The Bathtub. His cartoons ended with him running in front of a sign reading "A Looney Tune" and saying "That's all, folks!"
The Merrie Melodies of the same time would feature the star of the cartoon running in front of a drum reading "A Merrie Melody", only they would say "So long, folks!" Unlike Looney Tunes, these would change with every cartoon.
It wasn't until 1936 that both series started to use the now-famous script sign-off. The Looney Tunes shorts depicted the text being written on a black background, while the Merrie Melodies had it written over the bullseye. The first Looney Tunes to feature it were released in early 1936.
In 1940, Confederate Honey was released and the ending had the finalized "That's all Folks!" version which is being used today.
The first design was in 1936 with a lowercase "f" instead of an uppercase "F" in "Folks". In 1938 it was changed again. In 1940, WB created the finalized version.
1937's Rover's Rival made history by introducing Porky Pig's now-iconic sign-off. As an instrumental version of "The Merry-Go-Round Broke Down" played in the background, Porky Pig would pop out of a drum and say "Th-th-that's all, folks!" This was used until 1946, when the Looney Tunes series too adopted the standard script logo on the bullseye.
Starting in 1963, the opening and closing titles were redesigned and the phrase was dropped for both series. This change stuck until the series ended.
The phrase has returned in most Looney Tunes productions from the 1970s onwards.
Porky Pig returned to signing off the Larry Doyle-produced Looney Tunes in 2003.
The Looney Tunes Show featured its own variations on the gag.
- The ending of Daffy Duck's debut cartoon, Porky's Duck Hunt, depicts the duck frolicking around a prewritten "That's all folks!" end card.
- The Old Grey Hare ends with Bugs handing Elmer Fudd a lit firecracker. After the iris out, the "That's all Folks!" title card appears, prewritten, and the firecracker exploding off-screen, shaking the on-screen title card.
- Hare Tonic and Baseball Bugs end with Bugs Bunny bursting out of the Looney Tunes drum to say "Eh, and that's the end!"
- A few Blue Ribbon Merrie Melodies reissues, such as The Bashful Buzzard and Daffy Doodles, replaced "That's all folks!" with a generic "The End" card with no animation.
- The Bugs Bunny Road-Runner Movie begins with the "That's all Folks!" signoff. Once it finishes, Bugs places a "NOT" between the "That's" and "All" to show the audience that the movie is just beginning. At the end of the movie, as the signoff starts writing itself, Bugs pops on to stop it. It then erases and writes itself as "That's not quite all Folks!", and Bugs starts the ending credits. As the credits finish rolling, the title fades in as "That's really all Folks!"
- Looney Tunes: Back in Action ends with Porky attempting to say his catchphrase, only to hesitate when the lights turn off. Eventually, he gives up and angrily says "Eh-h-h-h, go home, folks."
- Taz-Mania episode "Willie Wombat's Deja Boo-Boo" ended with this line, with Taz doing Porky's signature stutter.