The 185th prohibition is that we are forbidden from eating the fats of a kosher animal.1

The source of this prohibition is G‑d's statement,2 "Do not eat any of the hard fat in an ox, sheep or goat."

This prohibition is also repeated and the punishment of kares explicitly stated.3 This applies if he transgressed intentionally, but if it was accidental, he must bring a chatos offering.

The details of this mitzvah are explained in the 7th chapter of tractate Chulin.