I'd be curious to see what folks have created for their HARP SF game, in terms of original artwork. Here are two things to kick this off, from an artist friend of mine, Marcus.
The books described the Cerans as follows: "The Cerans are large and very muscular reptilian bipeds. An average individual is well over two meters tall; many reach two and half meters in height. A Ceran has a very thick hide, which varies in color from light browns and greys to a rare pure white. Their legs end in outsized flat feet (without toes). They have two arms, each of which terminates in a large hand with three fingers and one thumb. The neck flares out in a large collar from the bottom of their skull reaching to their shoulder tips at the sides and equally far forward and back. A Ceran has two big forward-facing eyes, which flank a central oval membrane that allows them to sense heat. Two curved vestigial horns emerge from the skull above the eyes. Below the thermal membrane is a sharp protruding beak incorporating three nostrils for breathing and the sense of smell. The third straight vestigial horn grows out of the beak. Cerans have no obvious external ears – instead they have two small ear pits, one on either side of the head covered by thinner hide, which focus sound into their internal ears."
As an experiment, I asked Marcus to create a sketch or two of the Ceran based solely on the description (he's never seen the RPG books).
Here are a couple of his works in progress:
