Think these contrasting compatriots are on opposite ends of the gene pool? Think again! The Bisonorus is, in fact, two bonded Monsters of the same species but different castes. At birth, the pampered Emperor Bisonorus perches atop the rounded dome of an eager-to-please Standard Bisonorus, where it will spend the rest of its days. Despite this inherited hierarchy, the Emperor Bisonorus prefers giving head scratches to giving orders.