The Sqeeks are a race of yellow mice-like creatures that are from the planet Cheesicon V, and appeared in every single episode of the Revenge of Mortimer trilogy. When a Sqeek gets defeated, it turns into a stone statue. It was never stated if they are able to break out or just permanently remain in the statue form.
During the trilogy, Mortimer McMire controlled each one of them that was seen in the whole trilogy with mind-belts (although no visible belts are seen on the mind-controlled Sqeeks), except for a couple Sqeek Elders. When mind-controlled, their pupils are light red instead of black.
Many different kinds of Sqeeks are encountered throughout the trilogy, but the unarmored adult ones that require just one shot in order to defeat are the most common of all in Flames On Earth and The Sqeek Battle. Besides the amount of shots they need in order to be defeated, they behave exactly the same as the Sqeek Soldiers. They replace the yellow Vorticon Grunts and the red Vorticon Grunts in Flames On Earth and The Sqeek Battle respectively. They are the only creatures in the Revenge of Mortimer trilogy that are encountered in more than one episode.
The most valuable item in Flames On Earth is a stuffed toy that represents the Sqeeks, being worth 5000 points.