Drop your peanuts

To shit ones pants. This can be used both literally or figuratively.
To crap ones self usually due to, but not limited to being startled.

"Guy chill out, don't drop your peanuts!"
"Dude I just got attacked by a dog, I nearly dropped my peanuts!"
"I totally just saw this kid yard sale off his bike and drop his peanuts."
"That baby is a total peanut dropper."