If it's a comedy, expect to see someone sent flying. If they're depicted in fiction, they're likely to be a dangerous obstacle. If they are in a group, they are likely to go on an Animal Stampede.
If they appear in a game, expect a Smash Mook or maybe a Bullfight Boss. They are one of the truly tank-like species of animal in the world. They're not very smart, but they always use their heads. When portrayed in the media, rhinos are always hulkingly big, heavy, and intimidating herbivores that are known to have bad eyesight, short tempers, and a tendency to run down and trample (or gore to death) things that piss them off. Magic: The Gathering card 'Crash of Rhinos'