Is it possible to create a simple stun gun out of the materials that I have?

I’ve always been interested in making simple electrical circuits, although I’m not all that knowledgeable in the field. I’ve been trying to create a small device that can deliver a harmless yet somewhat painful electric shock. I made one by disassembling an electric stick of gum prank and adding an metal prod. Originally, the “gum” shocked you when you pulled the stick. I changed it so you pull the stick, which instead of shocking you, sends the electricity into a metal prod. I want to build a shocking device from scratch, but I don’t know how with my current (haha, “current”) materials. They are some assorted wires, batteries of the AA, AAA, and 12v varieties, tinfoil, electrical tape. If I need something else maybe I could dig it up. So, can I build one? How?