Putting any transferable pigment (e.g. eye shadow, slow drying ink, or face paint) on your thumb then drawing a line across a victims forehead whilst shouting "Simba".
1: So yeah i went to see the Lion King 3D it's really good
2: Oh? Who's your favourite carachter?
1: Probably Rafiki. Yours?
2: Mine's definitely *rubs thumb across forehead* SIIIIMBAAAH!
Prime example of a real life Lion Kinging