It is called a dead corpse or body.
Carcass
a mount
The word 'mummy' is generally used for a body which has been preserved over a long period of time. A recently-preserved body is usually referred to as 'embalmed'.
It is called a mummy
A specific item will usually be referred to as a 'trophy'. A more general term would be 'taxidermy', which usually refers more to the process by which the pelt, cadaver, or head is preserved.
The fossil that can preserve a whole animal is called a complete or articulated fossil. It occurs when the entire organism is preserved with all its anatomical parts intact, often due to quick burial in sediments that prevent decomposition or disintegration. Examples of complete fossils include the exceptional preservation of insects trapped in amber or well-preserved dinosaur fossils.
A mummy is the body of a person (or an animal) that has been preserved after death
consecration
"Mummy" refers to the body of an animal or human that has been intentionally or accidentally preserved. It is believed that in Ancient Egyptian culture, bodies were mummified in order to preserve the body for eternity in the afterlife.
a body preserved by drying
Sometimes they are referred to as bits of dead plants or animals. Others refer to them as fossils, or organic remains. If it is a decayed organism (either plant OR animal) it might be referred to as 'detritus'. If it's the final remains of a human being, it may be referred to as a corpse.
His body was preserved and he is in the National Postal Museum.
It is called a mummy.
A gap in the geological record in a body of rock is called an unconformity.