The animal control officer was a man who lived in Ba Sing Se, where he found and imprisoned as many stray animals as he could when he traveled around the Lower Ring to sell them to a butcher. Animals impounded by him never seemed to find their way home, or were never seen again.
The animal control officer kidnapped Momo and three pygmy pumas and attempted to sell them to a butcher, who would use them as food. However, before this deal was finalized, Momo was able to open his cage, as the animal control officer had left the key in the lock, and the lemur escaped along with the pygmy pumas, whom he freed as well. The officer and butcher soon returned to the cells to find them empty.