Conditioning one's ball sack by repeatedly enduring either self-inflicted or assisted blows to them.
A technique practiced by Shaolin monks in Shaolin Kung Fu that also goes by the names 'Groin Skill' or 'Gold Armour'.
Andrew: Tyler what are you doing to your coin purse?!
Tyler: It's called the Iron Egg Skill dear Andy, I'm going to have the balls of a god!
Andrew: How often do you get kicked in the nuts?
by peno91 March 24, 2015
Get the Iron egg skill mug.