Eat ass or become ass
You say it when you're about to do something so reckless it might get you dead or make you the laughing stock of the team.
"Eat ass or become ass" before I shot a grenade at a teammate.
"Eat ass or become ass" as I climbed on top of a tank in the middle of a battle.
"Eat ass or become ass" as I tried to take out an enemy by throwing a knife at their head from 20 feet away."