If you are into eating "all" of a butchered animal, then animal offal is your thing. In some cultures, the throat, heart, stomach, and brains of animals are considered offal delicacies. Bon appétit!
The word offal comes from a combination of the words off and fall with the idea that anything that's considered offal has "fallen off" the butcher's block — no one wants to eat that! Some people use these entrails and internal organs to prepare foods, which are sometimes called "sweetbreads," a somewhat misleading name for the offal faint-of-heart. Sweetbreads can refer to anything from the heart, to the tongue, to the testicles. Don't say we didn't warn you.