Sasha is a cursed Eevee, who constantly has two other voices in her head beside her own. The two spirits occupying her thoughts can control Sasha's sentient hair, in a way that can lash out and grab things if Sasha loses control. In her earlier life Sasha had a lot more trouble with controlling the spirits, but has recently learned managed to tame them to the point where she has full control most of the time. This gives her a lot more control over her size and the hair.

If you're curious, I also have a version of Sasha's reference without her coat and her boots. You can view that here! https://www.dropbox.com/s/wrb6ai6ot.....a%202.jpg?dl=0