- Needs to be inside, with a roof.
- Big space.
- Not much light.
- Not too close to another schlump.
If they are not in the right environment, they will disappear unless you pick them back up with the jar immediately. They are quite small at the start and hardly give you anything, but when you leave it for a while, it starts growing, giving you better gifts every time it grows. If a Schlump has two small heads coming out of his shoulders that means he is fully grown.
Schlumps can be very useful as they drop random items.