Rocky Mountain oysters, mountain oysters, prairie oysters, Montana tendergroin or swinging sirloin are American culinary names given to buffalo, boar or bull testicles. They are usually peeled, coated in flour, pepper and salt, sometimes pounded flat, then deep-fried.It is a well-known novelty dish in parts of the American West and the Canadian Prairies where cattle ranching is prevalent. The name is derived from the Rocky Mountains. In Oklahoma and North Texas, they are sometimes called calf fries but only if taken from very young bulls. In many parts of Mexico they are referred to as "criadillas" and are colloquially referred to as huevos del toro (literally, "bull’s eggs" but huevos is also a Spanish slang term for testicles) in Central and South America. Rocky Mountain oysters are sometimes confused with lamb fries or animelles (lamb testicles), which are served in a manner similar to Rocky Mountain oysters. Boar (hog) testicles are served in some Midwest areas such as in Illinois and Iowa. In other countries, testicles are known as sweet meats.The dish is most commonly found served at festivals, such as the ones in Montana and Phoenix, Arizona, amongst ranching families, or at certain eating establishments and bars that specialize in it. Eagle, Idaho has the "World's largest Rocky Mountain Oyster feed" during its Eagle Fun Days (typically the first weekend in June).In certain parts of the South United States, especially in December, Turkey Fries are on the menu and they come from the expected part of the bird. ReferencesEagle Fun Days, Eagle Chamber of Commerce