Meet the world’s most wanted parasite: a mummified caterpillar with a fungus growing right out of its face. Even stranger: it costs three times its weight in gold! This super-expensive fungus grows in the alpine regions of the Himalayas and Tibetan Plateau where it is cold and dry. Its promised health benefits include increased strength and cures for many diseases. Recently, it has become very popular around the world. Its price has increased and collectors have started harvesting more. But lately, some people have become concerned that the fungus populations are declining. We wanted to see if that is the case, and if so, why? So, we interviewed local harvesters and analyzed environmental models of the region. Our results showed that there is a decline in the caterpillar fungus populations, and the main causes are overharvesting and climate change.