"Earth pigs" are Combat Engineers, and a proud title that is !
I wore that title for a couple of years on Active Duty in the late '60s and a whole lot more as a second job in Guard and Reserve outfits as daughters kept showing up.
Hail fellow ! Well met.
I was changing my daughter when she was a couple months old and she started pooping when I got the diaper off. I called my wife in and said "Look. It looks like the ice cream dispenser at Ryan's Steakhouse." :D