A "Rhino" is the male version of Cougar. The term was intended to be derogatory. Reference to the rhino was used as a metaphor for horny, wrinkled and ugly.
Plainly stated, a "Rhino" is a male over 40 that admires the company of younger women. Rhinos will seek intimate relations w/younger women. The majority of Rhinos are very suave, have polished Game and are confirmed bachelors.
Some Rhinos are Sugar Daddies, but not all Sugar Daddies are Rhinos. Sugar Daddies may be of any age.