The beloved lion, famed for his black mane, was shot and killed by Minnesota dentist Dr. Walter Palmer during an expedition in Zimbabwe last month (Jul15).

The Tik Tok hitmaker is now speaking out against the slaughter on behalf of the Humane Society International and she's asking officials to act now and protect the world's remaining big cats, insisting they are heading for extinction.

In an article for Time.com, she writes, "I was heartbroken along with so many Americans who are mourning the terrible killing of the lion Cecil by a man from Minnesota. As an animal lover, I have traveled to Africa to walk amongst and view these stunning creatures in their natural habitat - taking care not to disturb them while also enjoying their presence...

"Sadly, these animals and many others face extinction from natural environments because of poachers and trophy hunters like Walter Palmer. It angers me that U.S. law currently does not protect African lions, and these “trophies” can flow across the U.S. border in unlimited quantities from anywhere...

"Poachers and trophy hunters from the U.S. and other countries are driving lions to extinction. This is the tragic reality. The U.S. must do everything it can to outlaw this perverted excuse for entertainment. As a Global Ambassador to Humane Society International I am joining with Humane Society of the United States and its international arm ­Humane Society International ­in urging the U.S. Fish and Wildlife Service to add the African lion to the endangered species list..."