Gargoyles in architecture were sculptures used to direct water away from roofs and keep it from running down the side of the wall. A cut in the back of the gargoyle directs water down through its mouth, usually. The length of the gargoyle determined how far away the water was directed from a building.
Besides this practical use, gargoyles have also been used to protect a place from evil spirits. Not all gargoyles were scary. Some were reminiscent of monks, animals, and people.
The church used gargoyles to represent evil because literacy was uncommon. They wanted to scare people into coming to church, and to show that evil was outside of their walls.
A more famous building with gargoyles is the Notre Dame de Paris. Also, the Chrysler Building in NY can be found hosting gargoyles. The Washington National Cathedral is host to a large collection.
There was an animated TV series titled, “Gargoyles”, that ran from 1994-1996.
Many different websites offer various gargoyle items available for purchase.
The above information and image is from Wikipedia