The original purpose of a gargoyle was to drain water away from the sides of a building. The word comes from the French "gargouille" which means "throat or pipe." This idea originated long ago, as samples of gargoyles have been found from ancient Greece.
Life without
Gargoyles (just plain rain spouts)
A half-done gargoyle
A fully evolved gargoyle

How in the World did they come to be
so strange?