your ass is grass and I'm the mower 

Approximates to: You just fucked up big time, and now you're answering to me! Originated in the military.

Commanding Officer: You tried drifting a Humvee till it went Tango Uniform and then blamed it on your bunkmate?! Your ass is grass, boy, and I'm the mower!

your ass is grass and I'm the mower by anonymous January 29, 2005

your ass is grass and i'm the lawn mower 

The expression of which your ass is grass comes from if you hear this you better get out of town because you're likely to get shot hung or end up with your head on a stick

Idiot1: oh dude I am so dead
Idiot2: yep that's quite a bit of a fender bender there
- idiot1 gets home-
Idiot1's roommate: heard you my moped just want you to know ass is grass and I'm the lawn mower
Idiot1:* shit himself*

And that my assholes is how the term:
Your ass is grass and I'm the lawn mower
Turned into: your ass is grass

your ass is grass and i'm the lawn mower by ಠ_ರೃ 1997 June 26, 2018