I don’t think I’ve ever heard someone say that at the start of a phone call but it’s common when communicating with two-way radios like:

“Alex for John, over”

“Go for John, over”

“<whatever Alex needs to say to John>”

I mostly heard that when working in large retail stores, usually the walkie talkies have an end-transmission sound que so we didn’t actually have to say ‘over’ at the end

Also a solid chance a regular housecat will defeat a level 1 wizard!

Not mine, but I remember an old d&d quip, maybe from tumblr: Door mat at the dungeon entrance with a sign that says ‘please wipe your feet’, door mat is a rug of smothering that attacks anyone who doesn’t >:)