One of the more interesting and less-developed races in Spelljammer were the stout grav, a race of miners who are able to manipulate gravity. The material presented for them makes no actual mention of a deity or faith that they follow or even priests, but it typically strikes me as unusual when races have no deities in D&D. Since the grav have featured heavily in the current leg of my Spelljammer campaign, it gave me ample opportunity to work on their culture and faith, and so I created the deity Kavor for them. Included with the PDF is the writeup for gravs as a PC or NPC race that I created as well.