A gargoyle was a Cardassian decorative object, carved in the shape of a Cardiassian person and/or animal, often found on bedposts.
On one occasion, the Arbazan ambassador Taxco resented sleeping another night on a Cardassian bed "with those gargoyles staring from the woodpoles." (DS9: "The Forsaken")
Since "Gargoyle" is an Earth term, Taxco likely referred to the figures as gargoyles due to the resemblance they bore with the medieval figures.