My mother had a friend who claimed to have previously been the head of a coven. She said she had been a witch, but I don't know whether she was Wiccan specifically.
She made all sorts of ridiculous claims, and scared the snot out of a lot of people who knew nothing outside their Christian upbringing (not bashing Christians here; it's just how it was).
She made a lot of claims that seemed to be no more than (what would on this forum be considered) fluff. And she always refused to elaborate.
She claimed to have controlled the weather, creating or dissolving tornadoes, as she called it.
She claimed the Bible calls Owls a "cursed" bird of the night, and that they really are eyes for "Satan himself!" Oh nose! But when I asked her where the Bible mentioned Owls since I was unable to find it and wanted to learn more, she refused to answer.
I could go on about things she claimed which could literally not happen, and some years later I realized she maybe got caught up in other things, and bought into the whole trying to scare good Christians out of going another way.
There are a lot of people who believe that literally impossible things are done by Wiccans, pagans, and other religions.
For instance, the rumor that Satanists (yes, the LaVeyan type) sacrifice children on Hallowe'en is propagated widely as a means to scare people away from not only exploring other religions but also from celebrating All Hallows' Eve.