paddleboat
A messy, loud way of pretending to be a dolphin. You pinch your own cheeks and go "brrr" like you're trying to scare a kid.
My cousin did a paddleboat in the middle of math class and got sent to the principal's office.
My buddy did a paddleboat in the cafeteria and got soup all over his shirt.
At the party, I did a paddleboat and got laughed at by everyone.