While its normal form is completely invisible (even while attacking), when the Phantom Fungus is killed or somehow made visible it looks like a brown or greenish-brown mass with a cluster of nodules at its highest point. The nodule cluster atop the main mass serves as its sensory organs. The creature feeds and attacks with a gaping maw lined with rows of teeth. Four stumpy legs support the creature and allow it to move about its subterranean environment.