Rhinos generally appear even-tempered, as Readers must realize. Nature has a system to guarantee an upbeat demeanor. It is called Aromatherapeutics.
Whichever way We turn, Rhinos (even disgruntled Rhinos) are greeted by stimuli and energies, bouquets of scent delivered by the breeze. How could We stay ornery when there are riches galore, tickling our fancies and priming our pumps?
Being grumpy is not a viable Rhinoption.