I don't know how to break it to you, but everything in Greyhawk was Gygax creating stuff as a joke.
Well yes, I know that in general.
But some of the deities are a bit more serious in conception, even if they focus on archetypes and stereotypes of other deities/pantheons.
Cheers
Side note: This is why I generally don't get the complaints about certain D&D settings or playstyles being "too silly". The setting that Gygax, the creator of D&D, made was about 90% jokes and 10% stealing from other IPs (Tolkien, Lovecraft, Moorcock, etc). He created iconic monsters such as the Displacer Beast (a black panther with tentacles sprouting from its shoulders), the Owlbear, the Rust Monster, the Gelatinous Cube, and the Beholder (a giant floating head that shoots laser beams out of its
11 eyeballs, 10 of which are mounted on eye-stalks).
"Silliness" is part of D&D's core identity. It's a silly fantasy game. Even the "serious settings" like Dark Sun and Ravenloft have super silly stuff in them (cannibal halflings, 6-limbed psionic ant-people, vampiric mind flayers, an ooze made up of the blood of a dead god that acts as a puppeteer-parasite for other creatures, floating undead heads that want to eat you, etc). D&D is silly. It's supposed to be. There is not a single setting in all of D&D (including homebrew and Magic: the Gathering settings) that isn't silly.
Most of the most iconic NPCs are extremely silly, too. Volothamp Geddarm (incompetent traveler-author of the Forgotten Realms that is perpetually super resourceful, but also super broke), Xanathar (aforementioned floating-alien-laser-head, but this one runs a crime syndicate and has a pet goldfish that he believes is immortal), Fizban (elderly, senile archmage avatar the Top God of Dragonlance), Iggwilv/Tasha (a witch raised by Baba Yaga that had an affair with the Demon Lord of hedonism and gave birth to a demigod, and rules over a demiplane in D&D's Fairyland), Minsc and Boo (One of them is a
Miniature Giant Space Hamster. Need I say more?), Jarlaxle Baenre and Drizzt Do'Urden, and so on.
/rant