This is just a little fun idea for younger grades. I often found my students' desks to become a disaster zone before the first month was over. Somehow there are students who can keep their desks organized and others who don't know what that means. But I found that if I reward students for clean desks, others often find they want to get theirs cleaned up as well.
Maybe once a week I would find 2 or 3 desks that were clean and make a copy of this reward to slip inside them (along with a treat). The next day the students would find them and be excited to show their friends. Word gets out that clean desks are rewarded, and the messy ones get organized so they can receive a treat. I definitely play it off like there is an actual desk monster.
This master copy is designed for 2 half sheet versions of the reward.