What is the "milk sac" inside a deer??

Question

My friend says that if punctured, it smells horrible. He said that it's purple with a lot of veins. I am just curious as to what the real name of this is and what it is exactly. Thanks.

Answer 1

It is the musk sac that male deer use to mark their territory with their smelly musky sweat.

Answer 2

i would go with your friend there