Gargoyles
Gargoyles were used for two main purposes. They were made with a spout for water to drain out from the roof, instead of going down the side of the building and ruin the walls. Gargoyles were also use to scare away evil spirits. The scarier they were, the better.
http://en.wikipedia.org/wiki/Gargoyle
http://en.wikipedia.org/wiki/Gargoyle