As I remember it,

When you hear the patter of little feet,
It's the whole First Cav in a full retreat,
They're movin' on,
They'll soon be gone.
They're burnin' gas, they're haulin' a**,
They're movin' on.

When the mortars started fallin' round the CP tent,
Everybody wondered where the high brass went,
[Continue as above.]

Doggie and Marine was on the line,
FDoggie says, "Marine, you're doin' just fine,
But I'm movin' on,
I'll soon be gone.
They're shootin' too fast for my little ole a**,
I'm movin' on."