Horror Construct

Picture
This horrible mesh of a creature is technically a type of golem made out of various other creatures' flesh. Not very many of these exist since necromancers don't practice this type of magic anymore. Most were just experiments, though some were used for various purposes afterwards, such as guards for lairs.
While the use of creatures was already dubious at most, the line was crossed when some humanoid flesh was used to make more powerful versions of the Horror Constructs, though those are even rarer to find than the Horror construct themselves.