It was an anthro scalie (I'm pretty sure) leaning on the rope of a boxing ring with an erection. I am 95% sure it had a knot, and I think it was of high quality, implying that it is a well-known artist.
Maybe with a dark background, maybe with his dick through the ropes like in post #1071235, but the situation I described.
Somehow immediately remembered the artist, and WOW did I misremember a lot about it.
Updated by BlueDingo