What is testicle cheese?

There is no such thing as "testicle cheese." That phrase is likely a misunderstanding or a joke.

It's possible someone was making a joke about the appearance or texture of a specific cheese, or perhaps they were referring to a type of cheese that is traditionally made with animal rennet, which comes from the stomachs of animals (including calves).

However, there are no cheeses specifically made from testicles. If you're curious about specific cheeses, please ask, and I'll be happy to give you more information.