The Stigorax were native to Terra Alpha. They hunted the Pipe People. When the humans came to Terra Alpha, they were almost wiped out, apart from one named Fifi. Fifi was tamed by Helen A, leader of the Happiness Patrol. Fifi obeyed Helen A's commands and was sent to hunt people who opposed her. Fifi was killed while trying to hunt down the Seventh Doctor, rendering the Stigorax species extinct.