A by-product produced by mostly old people who wear diapers, as well as babies. The shit biscuit is formed when they shit themselves, but doesn't clean up or get changed right away. Over time, the turd is flattened out (from sitting on it) and eventually hardens into a dried out biscuit or cookie-like turd.
"I went to the nursing home today to see grandpa, and I think he had been making a batch of shit biscuits."
by rockstarchris September 5, 2006
like a little kid getting on your nerves is a little shit biscuit cause idk they pretty much shit in a bag on their waist...oooh or a little black tar baby
"dude im tryin to play guitar hero nigger fuck off you little shit biscuit!!"
by julian_boredom December 25, 2007
1. A confectionary given to your enemys, consisting of:
Shit + Biscuits.
2. A curse for when "Oh FUCK!" just isn't enough.
1. I really hate that brian-face, I know what I'm going to bake him, shit! and biscuits! Shit-biscuits!
2. Oh Shit-biscuits! (realising youve forgotten to wear clothes whilst in the middle of a flight to Ibeza)
by Tom Glenx April 19, 2006
A fist full of human fecal matter that was acquired through an anal fisting.
Friend 1: "yo! I still got shit under my finger nails"

Friend 2: "nasty! From what?"

Friend 1: "from fist fucking some nasty bitch for shit biscuits last night"
by Robharry53 January 11, 2017
The term you use when all the cum is out of the penis
"Holy shit biscuits! All of my baby gravy is on your face!"
by Pullin Out with my Cock Out September 26, 2017
Phrase used to describe the impossible things in ones life that just shouldnt be able to happen.
Me: Whoa I just won the lottery twice in the past 2 weeks!

Friend: Well isnt that just some shit on a biscuit.
by Cat lover’s anonymous September 2, 2009