The name of the
god worshipped by the
Omnians in
Terry Pratchett's
standalone Discworld novel, "
Small Gods".
Usually Om appears as an enormous, flaming, anthropomorphic bull, when he bothers to appear to mortals at all, except for the time when he got stuck as a one-eyed tortoise for three years. Turns out all of his worshippers had been spending the last several years worshipping the church and statues of him therein, with the sole exception of Brutha. Fortunately, Brutha wound up being instrumental in changing things around and becoming the last great prophet of Om.
Since then, the Church of Om has broken up into more denominations than you can shake an incense burner at, but on the whole they're more sincere about it. So that's okay.