The Puft is a three-eyed, four legged flying creature with stripped fur.
It is passive and spawns in the Swamp biome. Pufts will not become aggressive even if attacked. They will not die unless they are killed, or starve to death. (Which can only happen onscreen) When killed, it deflates and all unused polluted oxygen is released as well 1 meat generated.
Pufts are comfortable at temperatures between 29 to 45 degree celsius. They die at temperatures below -30 degree Celsius and above 70 degree Celsius.
Pufts can be attracted with a creature lure
When a Puft breathes in enough Polluted Oxygen (50Kg???, breathing rate 175 g/s) and has enough space (at least two field high), it poops slime (again at a rate of 175 g/s). The slime decreases slowly in mass while again emitting polluted oxygen.
Pufts can be used in an infinite cycle to produce slime and thus oxygen: Place the Puft into a mesh tile cage that is 2 field high in a room that will keep the polluted oxygen in. Since polluted oxygen is a breathable gas Duplicants can reach the Puft to collect the slime without releasing it from the mesh cage.