From the Super Mario Wiki
“And so we hereby present an invigorating and inspiring dance of utter joy and happiness...”
Jerry is one of the Magikoopas from Mario & Luigi: Bowser's Inside Story that form the Magikoopa Mob. He and several others are trapped in a cage by Fawful and imprisoned behind a locked door in Princess Peach's Castle. After the Magikoopas are freed, Jerry and several others get into a squabble over what they are going to do to honor Bowser for rescuing them, much to the Koopa King's annoyance.