Malia was 9 years old when she became a victim in a car crash in 2003. Her body was never found. Her family was found three days after their deaths still trapped in the car and seemingly mauled by coyotes.
Malia is currently 17. She was born in 1994 based on her age at the time of the crash.
She is still feral in many ways and considers the world the way a coyote would. She has no concept of friends and does not feel any moral compunction about leaving people behind in order to escape a dangerous situation. She is, however, particularly attached to Stiles and claims that she would never leave him (unlike the others).
Malia is quick to fight and handles pain well. She has difficulty focusing her hearing and other enhanced senses as a human.
Scott finds an unfamiliar shapeshifter, a werecoyote, in the woods by the crash with eyes that glow blue. It turns out to be Malia. Scott surmises that she turned in the car on the night of the full moon, causing the car crash. It's unclear whether he thinks she suffered from the same bloodlust that a werewolf suffers from and would have mauled her family.
Malia stayed shifted as a full coyote for eight years. Scott is able to use the force of an alpha roar to shift her back into a human so she can be reunited with her father.
It is unclear whether her father has been told that Malia is a werecoyote.
In 3x19 - Letharia Vulpina, Lydia learns from Talia's claws that Malia is Peter's daughter. It is not explained why Talia would have stolen that memory, aside from Peter being a psychopath, given the timing of the car crash (2003) and the Hale House fire (2005).
Malia has accompanied Stiles, Lydia, Scott, and Kira to Mexico to find Derek. She, Kira, and Scott station themselves in the Calaveras' club as back-up. When it becomes clear that negotiations have gone sour, Malia dances with the crowd to blend in. She encourages Kira to so as well, only Kira dances terribly. In order to help her, Malia pulls her in close and starts grinding against her. Once the hunters notice them, however, Malia takes down one guard by lifting him up and smashing him into the floor. Kira and Scott each take care of a hunter on their own, and the three of them head up toward Araya's office. Severo releases wolfsbane gas into the hallway to stop them. Malia is as affected by the wolfsbane as Scott. They are all locked in a cell, and Malia suggests taking out the first person who opens the door and making a run for it, leaving Lydia behind. Kira asks her if that's what she'd do as a coyote, leave someone behind. Malia says yes, and that if it had been bad hunting she'd eat her first and then leave her. Stiles is distressed and reminds her that the rules of the wild don't apply to friends. It's clear they've been talking about social etiquette. Hunters come and take Scott and Kira, leaving Stiles and Malia alone. Malia tries to listen to what's going on, but she can't concentrate. Stiles kneels in front of her to help her, and she kisses him. The kiss makes her eyes flash blue, and she's able to hear with more focus. She reports that Scott is screaming and then that Scott said Kate has Derek. Stiles is stunned. Araya lets them all go and gives them Braeden to guide them to la iglesia where Derek is being held. On the drive, Malia asks who Kate Argent is. None of the others particularly want to answer, but they tell her that she killed Derek's family, was Allison's aunt, and is now a werecreature.
The Jeep hits something and comes to a stop. Stiles sends Scott on ahead, and while inspecting the vehicle Malia finds an antler or tooth stuck in the wheel well. She surmises that something hit them on purpose. While Stiles fixes the Jeep, Malia keeps an eye on the surrounding area. She can tell they are being watched. Night falls, and Kira uses her sword to bounce light from the headlights around for Malia to see better. They spot the thing watching them, and Malia takes off after it. She gets in a scuffle and comes back with a deep gash in her side. Stiles fixes the car, and they get going. He yells at her for running away because he was worried she was gone for good. Malia assures him that she'd never leave him, even though she would leave everyone else. The others aren't too thrilled with her candor. When they arrive at la iglesia, Stiles leaps out of the car and runs up to see Derek. Malia asks him if the person Scott's carrying is Derek, and Stiles replies, "Uh, sort of."
After they have been cured, Malia regains her eyesight and reads the deadpool list from Stiles's jacket. She sees herself listed as Malia Hale. When Stiles comes over to see if she's okay, she removes his hand from her shoulder when he touches her and then gets up and walks away without speaking to him.
Malia is seen in a hallucination Stiles has when he can't sleep. Malia goes down to the vault beneath the school and opens a safe with her adoption papers. She takes a look and Peter appears. Peter says " I gotta get a better safe." Malia and Peter talk to eachother and at the end before the scene ends, Peter says that he found her mother and heard that she's a desert wolf. Malia says that means coyote. Near the end of the episode, Stiles sees that Malia is attaching things to the board.