Azala is one of the main antagonist from Chrono Trigger, and the primary antagonist of the Prehistoric Era in the game.
Azala was the queen of the Reptites, a highly evolved race of humanoid reptiles that lived during the prehistoric age. The Reptites were in war with the humans for control over the land, but the Reptites were much more evolved than the humans at that time. However, the Reptites were extinct because of the fall of Lavos into the planet, which started a harsh ice age, which the Reptites were unable to survive.
When Crono and his friends arrive at the prehistoric age, they are attacked by a horde of Reptites, but Ayla, the leader of the humans of that age, helps them. She invites them to a big party in their village, where they end drunk and fall asleep. When they awake, they notice their Gate Key, the key they use to open the time gates, is gone. Ayla notice the footsteps all over the place, which belong to Reptites, so she accompany Crono to go after them. The key was with Kino, the second in command in the village, but the Reptites had stolen it. They go into a cavern where the Reptites resided, eventually finding Azala holding the key. Azala obviously doesn't know what is the purpose of that object, so she calls her henchman Nizbel to take care of the intruders. Nizbel is defeated, so Azala gives the key back to them.
Much time later, after Crono and Frog defeat Magus during the middle ages, they are sucked by a great time gate, ending stranded at the prehistoric age. Ayla helps them, but after they go to sleep their villages are attacked by the Reptites. Wanting to finish this conflict once and for all, Ayla decides to invade the Tyranno Castle to fight Azala, so Crono goes with her. They eventually meet each other in the throne room, so Azala invites them to go outside, where she calls her pet, the giant Black Tyranno, to fight them. Azala is defeated, but they notice that Lavos is about to fall into Earth. Ayla tries to rescue Azala, but she refuses, saying that her and her race's fate was already sealed. Ayla and Crono flee the castle, as Lavos falls over it, thus destroying the castle and extinguishing the Reptites.