A mythical cross between a rapper and rhino. Contrary to popularopinion, he is domesticated and even trained, he has fly beats and often carries birds on his back. He both has a horn and is constantly sexually aroused. He is not successful in rap, not making records or rhymes or getting paid for them, which means they don't get played. He is also not sexually active. He enjoys going to his grandmother's tea parties. Contrast with the somewhat more successful Hiphopopotamus.
Some other people on Urban Dictionary think the Rhymenocerous is or should be specified as not a large, water-dwelling mammal, but this is absurd, because it is well-known that the Hiphopapotamus is the one who finds it necessary to cite the fact that he is not a large, water-dwelling mammal.
A nickname for Chuck D, the MC of seminal rap group Public Enemy. Compared to other MCs, Chuck spits harder, more serious game.
From Public Enemy's "Rebel Without a Pause":
Yes the rhythm the rebel
Without a pause I'm lowering my level
The hard rhymer where you never been I'm in
You want stylin' you know it's time again
D the enemy tellin you to hear it