skull egg 

protrusions on a persons forehead, may be one or more, usually but not limited to, past middle aged himbos trying to recapture a lost youth.

Can be accompanied with pronounced veins surrounding skull egg that run down to the nasal area.

Skull eggs occur as the result of ingestion of all manner of substances, but most commonly the snorting of cocaine, heroin or secret injections of human growth hormone.

Can also be the result of botched platic surgery.

Jean Claude Van Damme has a nice skull egg growing on his right side forehead in movie Univeral Soldier: Regeneration.

Also Sly Stallone has Skull Egg development.

Gary Lyon, Australian Rules footballer and candidate for the Australian Yeti look alike award also has skull eggs developing.

skull egg by Mr Lucius Wolf January 3, 2010

Iron egg skill

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?

Iron egg skill by peno91 March 28, 2015