AaronOfBarbaria
Adventurer
I describe the absolute basics of what it looks like (i.e. "a tower of muscled flesh with a snarl of jagged teeth" for a grey render, or "an immense black winged lizard with acrid fumes for breath" for a black dragon), and get on to what it is actually doing.
Unless I've got a piece of art to show the players, the image their imagination creates is only going to be hindered by me trying to relay all the fine details, so I don't waste time doing that.
Unless I've got a piece of art to show the players, the image their imagination creates is only going to be hindered by me trying to relay all the fine details, so I don't waste time doing that.