- "As long as you stay in that chair Billy, that Dinosaur will be your friend."
- ―Papa Acachalla to Billy
Lettuce Squirrels are creatures resembling an Allosaurus. They seem to be a species of Dinosaur like shape shifters.
It was thought that the lettuce squirrels were extinct, but Papa Acachalla hid them so he could eat the last ones. After what can be presumed to be at least decades of waiting, Papa returned to the lettuce squirrel forest with his son Billy Acachalla on a vacation. Where they soon decided to hunt for the elusive creatures. Upon finding a lettuce squirrel, the two Acachallas were quickly overwhelmed as papa did not anticipate the creatures ability to evolve in ways similar to a Pokemon. Fleeing to a nearby hotel, Billy and papa were eventually able to deal with the first lettuce squirrel the encountered; only to be forced to deal with another. But just as Papa Acachalla was ready to give up hope, a demonic Sally Acachalla had arrived and devoured the lettuce squirrel whole . Though his life was saved, papa was quite traumatized by the experience. 
Years Later A group of lettuce squirrels, along with some regular/abnormal squirrels invaded the house of an unnamed woman who called Princeton Quagmire to exterminate them. After finding and killing two of them, an army of lettuce squirrels invaded the neighborhood. After a prolonged gunfight with Princeton Quagmire, They ended up killing him. However, his ghost returned and used an explosive device, which erased all squirrels, including lettuce squirrels, from existence. 
- The only way to prevent a Lettuce squirrel from attacking you is to balance yourself on one wheel of a chair. Billy is the one to discover this method of calming them.
- Lettuce Squirrels can also take the form of a creeper, indicating the possible ability to shapeshft.
- They are reskinned Antlion Guards.
- As of February 16th 2017 they no longer exist do to a nuke that erased them from the universe.