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.
Most Jews who mock God are mocking the Jewish version thereof, I.e. Judaism.
This seems more to fall into the category of mah ha'avodah ha'zos lachem than birchas Hashem.
Humour is a good way of unravelling society.