Tolypocladium ophioglossoides, also known by two of its better known synonyms Elaphocordyceps ophioglossoides and Cordyceps ophioglossoides and commonly known as the goldenthread cordyceps, is a species of fungus in the family Ophiocordycipitaceae. It is parasitic on fruit bodies of the truffle-like Elaphomyces. The specific epithet ophioglossoides, derived from Ancient Greek, means "like a snake's tongue".