Aquila is a female bald eagle, and the second mate of Ornen, the leader of a group of bald eagles in Ambala. Unlike her mate, she is young, while he is old and scarred. She is very wise and caring for her young age, and once took in a wounded owl chick to care for until it could fly. She also was the one who convinced her mate and his group to participate in The War of the Six Kingdoms, while he was reluctant due to his age and scars from previous battles. She is a friend of the Guardians, and tells them that "underneath those dirty feathers and scarred features, lies a caring, fatherly, and handsome bird." She has made many visits to the Great Tree, and has been known to sing occasionally while there, and has been told by Thradora Plonk she "has a good Contralto". She is a good friend of the Snowy Owl, and sometimes Aquila sleeps in her apartment. Ornen does not approve, as he thinks "She's an eagle, not a blasted owl, what's she doin' singin' an' sleepin' in a frinkin' owl hollow, for Avia's sake?!"
During the War of the Six Kingdoms, she learned and mastered Danyar, much to Ornen's frustration. However, when she saved his life by using the technique, he was very grateful, and promised never to make fun of her owlish ways again. Afterward, they even came to the Great Tree for the feast.