A Non-Functioning Gargoyle Is Known As What?
Answer: A Grotesque
Although the term “gargoyle” is commonly used to refer to any sort of statue-like ornamentation that decorates the corners and pinnacles of buildings, traditionally a gargoyle is a functional piece of ornamentation that directs water away from a building. Gargoyles were commonly designed as screaming creatures, demons, or animals precisely because their open mouths were practical termination points for the gutters directing water off the roof.
A statue that appears to be a gargoyle but serves only a decorative function is known as a grotesque–traditionally the same styling as a gargoyle but sans the practical use of redirecting water.