The general term “fungicolous fungus” refers to a fungus that is consistently associated with other fungi (Fig. 2; Gams et al., 2004; Hawksworth, 1981; Sun et al., 2019). Researchers may also refer to fungi as fungicolous when the exact nature of the trophic relationship is not known (Barnett, 1963; Barnett and Binder, 1973). A distinction between hyperparasites, mycoparasites, and fungicolous fungi is made in the literature for several reasons. First, hyperparasitic fungi are frequently studied for their potential use in biocontrol of economically important parasites and pathogens (Brotman et al., 2010). Second, they represent an opportunity to study trophic cascades and natural dynamics of predation in both host and parasite populations (Fig. 3; Parratt and Laine, 2016). Finally, parasitism of another organism that is strongly or obligately reliant on a specific host, has potential impacts on the dispersal and evolution of that organism, which parasites of non-pathogens may not experience.