The cooler monster is a creature that Dipper Pines finds in the ice cooler at the Dusk 2 Dawn. It is unknown whether this is an independent creature or simply a creation of Ma and Pa's own design. The latter is more likely, as the cooler monster is gone when Dipper checks the ice cooler again.
It resembles a human brain with veins hanging off of it, some of which form hands, two retractable stalk eyes, and a mouth that looks like a pair of dentures. It is surrounded by a blue aura, similar to the things that are possessed or used by Ma and Pa Duskerton. It is possible that the veins are actually the human nervous system, as it all stems from the brain.
- 105. "The Inconveniencing"
- When he was asked if the cooler monster's appearance would ever be explained, Alex Hirsch simply replied: "No."