I think most people refer to those creepy statues at the top of old buildings as gargoyles. I do sometimes. And I am incorrect.
This is one of those things that I`ve known for a long time, and still say it the wrong way. That awesome animated series from the 90`s probably doesn`t help.
Technically, a gargoyle is a piece of statuary with the purpose of channeling water off the roof and away from the exterior walls to prevent mortar erosion. This is most common on Gothic architecture found in Europe, North America, and elsewhere.
The term gargoyle comes from the French world gargouille, which means throat or gullet in English. This is probably in reference to the water being routed out of the mouth of that statue and the gargling sound it makes.
So what do you call all those other purely decorative statues? The correct answer is grotesque. That`s where the English use of the word comes from, because these things are often quite grotesque.
I find it interesting that gargoyles and grotesques are most commonly found on churches. There are more simple ways to evacuate water, after all.
Some say they are to ward off evil, some say they represent evil, while others think that the imagery helped assimilate pagans into Christianity.
I just think the artisans had a dark design aesthetic.