Procrustes

The Lightning Thief
Procrustes, although he introduces himself as "Crusty", is a monster who appears briefly in The Lightning Thief. He is also called the Stretcher, due to his unfortunate tendency to tie travelers to two bent pine trees and stretch the victims until they tear in half. In the Lightning Thief, he is the owner of a Los Angeles mattress store. For his stretching habit, all of the beds are rigged to snare anyone who lies down on them with ropes and extend them to exactly six feet. If they are over six feet, the excess is removed by Procrustes with a very large battle axe.

Percy, Annabeth and Grover encounter Procrustes while searching for the gate to the Underworld. He seems to be kind, although frightening in appearance, and invites them to hide from several gang members in his store. The monstrous salesman tricks both Annabeth and Grover to lay on mattresses, thereby trapping them, but Percy remains free and convinces Procrustes to lie down himself. Once the snares have been triggered, Percy releases his friends and cuts Procrustes down to size with the giant's own axe, thereby destroying him.