Titled Eveready Harton in Buried Treasure, this is entirely NSFW.
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The story goes that Walter Lantz (Woody Woodpecker), Max Fleischer (Popeye), and other animators worked on this in their spare time and presented it as a birthday gift to Winsor McCay in 1924.
The last thing I expected to see today was a 1924 cartoon featuring bestiality (cows! dogs! donkeys!), a woman with a dildo, homosexuality, and a dude loading his massive penis on a handcart.