It’s impossible to give a definite answer to such questions like ”What does my mum/dad/son etc. look like after spending years in the grave?” because it varies greatly (depending on the climate,soil type etc.) and each individual case is unique. It is impossible to know the macabre answer unless you exhume the body..As a matter of fact, decomposition is faster in temperate climates and sandy porous soil (because the decomposition process requires oxygen). Due to this reason, (the ability of breaking down organic material into simple forms) when they establish and open a new cemetery/burial ground, sandy soil is preferred over clay..Dry, low-humidity climates can lead to mummification, as the skin dehydrates and brownish,leathery appearance occurs…On the contrary, when the climate is too wet and cold, the water-logged graves might turn bodies into wax corpses which is caused by adipocere formation – a form of ‘mummification’ ; then the skin has a greasy,waxy look with mold growing.. When forensic examiners determine the time of death, they use ”Casper’s ratio”..when there is free access of air, a body decomposes twice as fast than if immersed in water, and eight times faster than if buried in earth..Under normal circumstances, a human body shows the external signs of decomposition within first week (3-to-7 days). According to Casper’s ratio, it is equal to around 20-50 days when the body is buried underground,depending on the depth of grave,how deep it’s dug..(shallow burial=faster decomposition) and the type of casket/vault (access to oxygen). And as a matter of rule, autopsied bodies (or any trauma) rot faster,regardless of embalming,whether embalmed or not. And plus, depending on medications (or drugs) that the deceased person was taking, can adversely affect the embalming fluid (one of the reasons why late Anna Nicole Smith was decomposing faster than expected). Wooden or metal casket? Wood allows faster but natural decomposition whilst rubber-gasketed metal caskets keep the remains longer; but might create this smelly stew,mushy skin (like those ‘undead’ zombies you see in horror movies). An unembalmed body that’s buried in a wooden coffin (most likely) starts to decompose between 1 and 3 months (depending on the season of the year) but as i said, each case is unique and there is no definite answer. But it shouldn’t really matter ,since they are no longer our ”loved ones” but rather empty shells,that’s why we call them ”remains”… I heard from so many people attending a viewing/open casket funeral saying ” That wasn’t my mum/dad/grandma etc. in the coffin” . The person is gone when the body is deprived of the life of the spirit, it’s just like when you cut your nails or hair, it’s not a part of your body anymore..