Waste monsters resemble Nitrome's depiction of poop. Waste monsters have a swirly brown body, that gets smaller as it goes up. The creature has two eyes, one of which is squinting and twitching. It has green lips, and its tongue is sticking out slightly.
Waste monsters try to home in on the player, whenever possible. Waste monsters will work together to trap the player if multiple waste monsters are found in a level. Every twenty to thirty seconds, waste monsters will cease movement, appear to be straining, open their mouth, and start sweating, then have a relieved expression on their face, then walk away. Waste mines (poop) are left in the area where they stopped.
This waste will harm the player if it walked over, like other dangerous enemies and objects, but not disappear once this is done. After fifteen to twenty seconds, the waste will disappear, but all waste monsters in the level will proceed to leave another "waste mine." All the waste monsters in a level will lay "waste," all at the same time, no matter where they are.
- Waste monsters bear a strong resemblance to the ice cream characters of Bad Ice-Cream, particularly the chocolate ice cream. Nitrome's use of "poop" in other games came after Bad Ice-Cream.