Sheep testicles are actually more common. Bull testicles are a bit more rare, and generally come from old bulls. Lamb testes are pretty big, and absolutely delicious.

Here in Sao Paulo, theres a dinner that serves fried rooster testicles.

People will eat the strangest things if they believe it will make them more "manly".

Which is doubly weird where in Texas there's nary a mountain found.