Farmer: "The Stompers are your worst nightmares"
Jimmy: "I know, I know—that is all I hear about them! They are scary, they are horrible, they are worse than anything I can imagine. Just tell me what they are, please!"
Farmer: "No, Jimmy, you are not hearing my words. I am not speaking in metaphors—there is no time for that now."
Jimmy: "What...what do you mean?"
Farmer: "The stompers are your worst nightmares"
— Farmer to Jimmy Fincher

The Stompers take control of people in the Yumeka, after they are put into the Black Coma by the Shadow Ka. They relive the person's worst nightmares—except for real. They feed on the person's fear.