It all starts out looking like a green blob (which reminds me that I might want to paint Slimer one of these days) ...
One of my favorite drawing teachers in college would always say to "give them a place in this world" ... or rather, don't make the mistake of letting your subject float around in space.
So I had to give him a place in this world. A Louisiana bayou ... not unlike his last hangout, the swamp planet of "Dagobah".
"Born on the Dagobayou"