Is there an issur for a Jew to mock God by means of satire or a joke? is joking about God halahcically distinct from "birkas hashem," (cursing God) which is prohibited even to Bnei Noach (per Sanhedrin 59b)? The only source I can think of that directly addresses scoffers is Tehillim 1:1 ובמושב לצים לא ישב. Can you think of any others, be they biblical or rabbinic?
The גמרא says in סנהדרין דף סג עמוד ב:
אמר רב נחמן כל ליצנותא אסירא חוץ מליצנותא דעבודת כוכבים דשריא
All mockery is forbidden other than that of idol worship.
So, there is a general prohibition on leitzanus, even without referencing God. I don't think you will be able to find any sources explicitly referring to ליצנות of God, as all ליצנות is forbidden.