Atala is the head trainer for the Hunger Games. Her job is to explain the point of each station, the possible ways to die in the arena, and to get the tributes in shape to compete. It is said in the Tribute Guide that Atala can whip even the weakest tribute into shape.
The Hunger Games
Atala is first seen in The Hunger Games when Katniss and Peeta join the other tributes for training. They stand in front of her in a semi-circle. She welcomes the twenty-four tributes and then explains to them about the different stations set up around the training center. She, as usual, reads through the list of stations, explains there is no combat allowed with other tributes, and that survival skills are just as important as fighting skills. She then releases the tributes to train. While training, Cato and the District 6 male get into a fight over Cato's stolen knife, which was actually taken by Rue. Atala is heard blowing her whistle to get their attention and tells them to get back to training.
In the movie Atala stresses the survival stations and warns them that many die from natural causes in the games. She explained to the tributes: "In two weeks, 23 of you will be dead. One of you will be alive. Who that is depends on how well you pay attention over the next four days, particularly to what I'm about to say. First, no fighting with the other tributes. You'll have plenty of time for that in the Arena. There are four compulsory exercises, and then then rest will be individual training. My advice is don't ignore the survival skills. Everybody wants to grab a sword, but most of you will die from natural causes. 10% from infection, 20% from dehydration. Exposure can kill as easily as a knife."
Atala reappears in Catching Fire when Katniss and Peeta return for the third Quarter Quell. Again, she welcomes the tributes and then directs them in their training. She, as usual, reads through the list of stations, and then releases the tributes to train.
Her fate was not confirmed by the end of Mockingjay. Since she worked at the Games, it can be assumed she is executed as Haymitch mentions Capitol officials, people working at the Games, torturers and more were being executed. However, as she helped tributes survive the Hunger Games, it is possible she was spared, like Caesar Flickerman.
According to the text, Atala is tall and athletic. In the film, she is portrayed as being dark-skinned with black hair tied back in a loose ponytail and dark eyes. Atala's training outfit has the Capitol seal visible. Unlike most Capitol citizens, she looks pretty normal to a modern or district-oriented perspective.