From molds and yeasts to the mushrooms we fear and love, fungi are connected to life and death on our planet — but they're often misunderstood. We only know about 10% of the estimated 3.8 million species that exist. Do we need to be afraid of things like fungus zombies? We asked astrophysicist Neil DeGrasse Tyson and mycologist Giuliana Furci to help us understand this vast kingdom, and separate “fungal fact” from “fungal fiction.”