What a corpse looks like after being burried 12 years?

Already a few months prior after being buried, the body is already decaying. The body builds up with gas and has nowhere to go so the body becomes bloated thus attracting insects that break down the body and eat away as it progresses through the decaying process. The body goes through 5 stages of decay and thats autolysis and putrefaction. Autolysis, the body's enzymes begin to go into a meltdown and its sped up by extreme heat and slowed by extreme cold. Putrefaction is the bacteria that escapes from the body's intestinal tract and actually begins the process of literally melting the body down. Black purification is when the skin turns black and the corpse collapses and the gasses escapes. Fermentation is when the strong odors develop and there will be surface mold but the body has begun to dry out. Dry decay is when the cadaver has mostly dried out and the decaying process has slowed considerably. This when it starts taking longer but all the nasty stuff is over. So after twelve years and all that happens within the first years of being dead with or without a coffin at that. But in the end the body will be fully decomposed in 8-12 years and all that is left are the bones.

It depends what the corps has been buried under for 12 years because their has been incident were they hid the bodies in mud and they were preserved but if the corps has had contact with air then it would have probaly decayed