Minecraft wiki entry for Witch, associated text: Before the Java 1.18 update, Witches have an unused purple hat layer in their texture file, similar to the illusioner's hat.
The same hat layer is also present in the vindicator and evoker's texture files, where it is also unused.
These hat models also used to exist in the nitwit, librarian, and priest's textures before the Village and Pillage Update.
Witches were referred with female pronouns in an action figure box, making witches one of the few mobs to have a confirmed gender.
In the Village and Pillage Update artwork banner, the witch in the picture has its arms unfolded like a pillager, despite this being impossible ingame.