A form of flatulence resulting from the consumption of a large quantity of fast food hamburgers and ketchup. Typically, a ketchup fart will have an odor similar to the fast food hamburger and ketchup before their consumption; those that smell a ketchup fart are often disturbed by this fact.
A heavenly biscuit occurs when a man copulates with a pregnant woman ("bun in the oven") that has a yeast infection. The intercourse involves so much yeast that a chunky "halo" is revealed, circling the outermost point of penetration on the man's penis.
Jeff was really excited that this pregnant chick was DTF, but he sorely disappointed after he realized he was a victim of the heavenly biscuit.