Epizoanthus planus is a flat-forming epizoic zoantharian (family Epizoanthidae) with thin encrusting colonies of small polyps on marine invertebrate hosts in tropical seas, incorporating substrate particles into the coenenchyme. The systematics and species boundaries within Epizoanthus remain an active area of research requiring integrative molecular and morphological approaches. Genomic data have been generated for this species and are available in public databases, enabling comparative studies of cnidarian evolution and ecology.