Mountain Oysters can be eaten and several people still do eat mountain oysters which are essentially bull testicles.
I personally would not eat them but some people do enjoy them.
The Bull Testicles are called Rocky Mountain Oysters or even just Mountain Oysters because they changed the name to be more appealing as the name bull testicles were not appealing to many people and they had no luck selling them as bull testicles so they changed the name to Mount Oysters to increase the sales of them.
Most people who've eaten Mountain Oysters describe the taste of Rocky Mountain oysters as “rich.”
Others who have eaten the Mountain Oysters have said they taste like liver, and yet others describe them as veal cutlets.
Mountain Oysters are also known as lamb fries, bull fries, Montana tenders, huevos de toro, cowboy caviar.
The Mountain Oysters originated in the North American West, far from any ocean.
Created by ranchers, Rocky Mountain oysters are in fact, most famously, bull testicles.
Though sheep, bison and pig can be used, too.
The rocky mountain oysters are infamous in the Rocky Mountain region of the United States, usually battered and deep fried.