See, but Belkar doesn't have worshippers or anything. On the other hand, Popcorn has had a minimum of 50 years of worship (panel 3) and probably much more based on the fact that Soda looked much older when he finally hunted down Pizza.
Even wilder crack theory than Popcorn here that will almost certainly never happen: there's a lot of discussion going around about Banjo and/or Giggles becoming a fifth quiddity, but what if it's Belkar???? A common fantasy trope is that gods have to die to ascend, or that they're dead anyway. Also, I don't think deities need to breathe.
...y'know who's only appeared once? Giggles. Maybe there is something to that theory, after all...