Answer:
Alone I am 24th with a friend I am 20. Another friend and I am unclean.
I have a neck but no head arms but no hands. What am I?
I have cities with no people forests with no trees and oceans with no water.
Long and thin red within with a nail at the end.
A single syllable do I claim black was my most famous name; Fetal to mortals here below thousands have I slain in a single blow.
What can you lose that will cause other people to lose theirs too?