Brittney Donegal is one of Edilio's soldiers who is killed during Caine's attack on the power plant in Hunger. She has a regenerative ability, making her nearly invincible (it has not been established whether total destruction of her body e.g. total incineration would destroy her). Although she was thought to be dead, and was buried, she dug her way out and walked among the living in Lies. She has no heartbeat, which suggests that she is not truly alive. She needs no sleep, food, or water. Brittney attended Coates Academy, and was evidently in Jack's history class.
The image of her little brother Tanner, who died in the Thanksgiving battle, told her that she was brought back by God as an angel in order to destroy The Demon (Drake Merwin). However, it is revealed that the image of Tanner is just a ploy of The Darkness. The Darkness used Brittney's immortality and Lana's healing powers to give Drake Merwin a second life, but to do so, it had to put Brittney and Drake together. Thus, the control and form of their shared body oscillates between Brittney and Drake. At the end of Lies, Brittney and Drake together, as one, are kept in a basement in one of Perdido Beach's houses, guarded by Orc and Howard. Brittney wants Sam and the others to kill her, because that would mean Drake's death too, but Sam doesn't want to do this because it seemed to him like murdering an innocent girl. He is also uncertain whether it would be possible.
Brittney is one of four avatars Astrid sees when she is sucked into Little Pete's game. Her Avatar is neither male nor female and has metal teeth and a whip. At the end of Plague, she joins the Darkness because she believes it is God, after it has convinced her of its plan to rule the FAYZ, and then the world.
In Fear, she and her "body-partner", Drake, continue to serve the Darkness. She refers to the Darkness as the "Lord," as she once referred to her Christian God. She says it is better to have a God which one can see and feel than an invisible God, like her previous one. She is a fanatic follower of this strange God.
Brittney is described to be an overweight teenager with acne. She has light brown hair split in two ponytails, and braces that are constantly mentioned in Lies. The braces are also the first thing to appear during her regular transformation from Drake. The braces turn to liquid, leaving Drake/Brittney's teeth looking like metal. She had a crush on Mike Farmer before being killed and brought back to life. Quoted from Brittney when Mike urged her to leave with him "I'd rather burn in the fiery pits of Hell five times over than disappoint Edilio."
It is assumed that when Drake dies after the FAYZ, Brittney died at the end of Light along with him.
Even though described as overweight, on both the back of Lies and Plague, she is seen to be thin and healthy and does not have acne.