Beetlejuice from the Howard Stern show might have a death wish ... 'cause he's calling out one of the baddest men on the planet, Mike Tyson -- saying he'd beat his ass in a boxing match.
Remember ... Beetle's undefeated as an amateur boxer (remember when he fought Big Poppa?) ... and says he's truly confident he can hang with the top fighters in the sport, including Mike.
"Mike Tyson is a p***y," Beetlejuice said ... "He's scared of me."
Beetle -- who was out in NYC promoting his new Beetle's Juice E Juice -- also called out his longtime rival Floyd Mayweather .