OK, I'll bite. What's that?
Pretty disgusting. It involves cutting away flesh from a live animal.
I did a Google search. It is a sheep farming process, where folds of skin are cut away to prevent "flystrike." Flys lay their eggs in the folds and the wool gets infested with maggots. The animal people feel that this is inhumane, because no anesthetic is typically used, and because when sheep are mulesed, it is impossible to identify which ones have excessive skin folds, so this trait continues to propagate.