In the film "Maleficent", Maleficent talks about her wings in the third person, using the term "they", like a separate entity. She says "My wings were strong and true, they never let me down, not even once.", like they were some person or thing she could rely upon.
After being cleaved from her torso when Maleficent was in a drug-induced sleep by Stefan, her wings did not die. In fact, they remained alive and well. Sixteen years later, Stefan is now king, and apparently a bit insane as he keeps the wings caged up on display within glass and metal-cross bars, sometimes having "conversations" with them.
Then, later in the film:
On the day Maleficent arrived to save Aurora, Maleficent's wings flapped violently enough to escape from its cage with the help of Aurora. The wings then flew and attached themselves onto the back of Maleficent, as if they had a mind of their own. Maleficent appeared surprised, indicating she had no awareness this was going to happen.
What is the explanation of this in canon? Is Maleficent composed of multiple beings or entities or is Maleficent simply immortal and no part of her really dies. In the movie, it appears she ages much less so this hints at her immortality. The 3 fairies that raised Aurora did not appear to age at all.