This is a pair of magical creature ears from Ridley Scott's 1985 fairy tale, Legend, starring Tom Cruise, Mia Sara and Tim Curry.
For a long time I couldn't place these ears to any character. The fact that they were dark green/bronze-ish with glitter and the film being so dark, I tried in vain to match them to the creatures in the film. Only the goblins were dark-skinned and their ears were very different from these, much more pointed.
Until I found, in the extras of the Ultimate Edition DVD, the continuity polaroids for some characters, and there they were. They clearly belong to the creature (what is it?) sitting on the banquet table in Darkness' lair, during Lily's seduction scene. In the film, the scene is so dark that you can't see any features of the creature, but under the clear light of the Polaroid it is clearly unmistakeable.
And here are images from the Director's Cut of the film.