Random Wiki of the day: Oysters (fowl).

Oysters are two small, round pieces of dark meat on the back of poultry near the thigh[1], in the hollow on the dorsal side of the ilium bone. Some regard the "oyster meat" to be the most flavorful and tender part of the bird, while others dislike the taste and texture.

Compared to dark meat found in other parts of the bird, the oyster meat has a somewhat firm/taut texture which gives it a distinct mouth feel.