Having trouble with dieties that grant this domain. Like Apsu says dragon subdomain... Is Saurian available?
How would u do a cleric of sobek? I was thinking of making a faster cleric who rides on a stegosaurus mount
Google is your friend. I don't think Paizo has published much about him, but there's plenty about him on the web since he is borrowed from Ancient Egyptian mythology. See his wikipedia page to get started.
It contains gems like "Sobek was considered a violent, hyper-sexual, and erratic deity, prone to his primal whims. The origin of his name, Sbk[5] in ancient Egyptian, is debated among scholars, but many believe that it is derived from a causative of the verb "to impregnate." "
and "Sobek is, above all else, an aggressive and animalistic deity who lives up to the vicious reputation of his patron animal, the large and violent Nile crocodile. Some of his common epithets betray this nature succinctly, the most notable of which being: "he who loves robbery," "he who eats while he also mates," and "pointed of teeth."[13] However, he also displays grand benevolence in more than one celebrated myth. "
For a game though, you've got a lot of lattitude (and very little canon) so pick an aspect that resonates with you, and run with it. The main thing is you'd presumably be Osiriani (or possibly from somewhere in the Mwangi or thereabouts that had Ancient Osiriani ties).