Plenty of Christians make fun of Christians. That’s half the schtick at the Babylon Bee. Catholics have Catholic ridicule, Orthodox had “The Onion Dome.” Jews make fun of Jews.
No way is Islam funny, though. Never.
Jeff Dunham pushed closer than most with "Achmed, the Dead Terrorist". If he named the character "Muhammad, the Dead Terrorist", he might well be "Jeff, the dead comedian".
I looked up the Onion Dome. I think it’s about Orthodox Christianity.