It straightly depends on PKR. For example Amdromica died quite a lot and here's an example what you see when try to trophy her corpse:

Your wrath EVISCERATES Amdromica!
Amdromica is DEAD!!
You land the killing blow against Amdromica.
A zombie of the dwarven smith groans and topples into dust.
A zombie of the old dwarf groans and topples into dust.

48%hp 41%m 61%mv -indoor- [7 AM] 19099tnl civilized>
They aren't here.

48%hp 41%m 61%mv -indoor- [7 AM] 19099tnl civilized>
trophy corpse
The burnt corpse of Amdromica is not worthy of a trophy.

By game mechanics it isn't worthy.