Doughnut in the forehead

"Jackass-like" stunt by Klaas: in Tokyo, he got injected a salt solution into the forehead which formed a doughnut surface there. This is math extreme.

Joko Winterscheidt and Klaas Heufer run in Germany the show "Joko gegen Klaas - a duel around the world" The two ex MTV-moderators visit Asia and America and pose impossible questions to the other. The winner is the "world champion". The above "stunt" is from one of the shows.