The Scarlet Empress sent Iris Wildthyme to bring her the Four, believing one of them had the jar containing Cassandra, the first Empress. In exchange she promised to cure the dying Wildthyme.
By the time the mission had been accomplished, Gila had reverted to being an alligator with no trace of humanity. After Cassandra had been freed, she killed the Empress, who had imprisoned her originally. Gila ate her corpse afterwards, also consuming some of the pink life-giving gel she had basked in. (PROSE: The Scarlet Empress)