Doots are a designed species created to work as drones/workers by a multinational company dabbling in genetic engineering. The most simple description of them would be to picture a hybrid between a sugar glider, and a jungle possum. Out of each profession, these were the ones that were successful, though the company failed before they were able to mass produce them.
Spiro is a defective firefighting model, designed to help injured out of burning buildings and stop fires. As such, he's fireproof and has a reinforced right shoulder for breaching doors. His personality seems to be a bit sporadic and a tiny bit ditzy, especially with his tendency to carry a small squirt bottle most of the time.