He's pranked Madonna, Will Smith and Adele ... but his next victim could be his cell-mate Bubba.
Vitalii Sediuk faces jail time for crashing the Grammy Awards stage and messing with Adele's moment at the February ceremony ... TMZ has learned.
The 24-year-old Ukranian ran onstage ahead of the singer's acceptance speech and spoke into the microphone before Jennifer Lopez shooed him off. He's been charged with entering a performance area and interfering with performers ... both misdemeanors ... and faces six months in jail and a $1,000 fine for each count.
He'll be arraigned May 31.
Remember -- this is the guy who tried to kiss Will Smith on a red carpet in Moscow ... and got slapped down for it. His first trick was to hand Madonna a bouquet of hydrangeas -- knowing full well that they are the Material Girl's "most loathed" flower.
Wonder if he has any pranks involving soap on a rope.