Shmoo first appeared in the Li’l Abner comic strip in August 1948 when Li’l Abner discovers Shmoo after he enters the forbidden Valley of the Shmoon. Ol’ Man Mose begs Li’l Abner not to enter the Valley of Shmoon, claiming that the Shmoo are the greatest menace to society because they are too good.

But how can something be too good? After all, Shmoo love to help people by any means possible. They even delight in being eaten! Shmoo can taste like anything you are in the mood for – just fry for chicken or broil for steak. Eat Shmoo raw for oysters on the half-shell. No need to bother running out to the store, because Shmoo lay eggs and produce milk. Their eyes can be used for buttons, their whiskers for toothpicks. Cut their hide thin for fine leather, or thick for strong lumber. And it is not even possible to run out of Shmoo, because they multiply at such an amazing rate. Lil-Abner.com says “The Shmoo believed that the only way to happiness was to bring happiness to others.”

However, Ol’ Man Mose was right. The Shmoo did indeed cause society to break down, because with an unlimited supply of Shmoo, people no longer felt the need to go to work and society ceased to function. So, in an effort to maintain status quo, Al Capp had the Shmoo hunted down and supposedly extinct by the end of 1948, although later revivals made it seem as if at least one Shmoo always escaped.