Gooper Blooper Volley

Gooper Blooper Volley is a Special Game in Mario Power Tennis. It was set on the Gooper Blooper Court, situated in Ricco Harbour on the platform where Gooper Blooper is fought for the second time in Super Mario Sunshine. Gooper Blooper appears as the opponent, using all four of his great tentacles to volley the tennis ball back to the player. The player must avoid hitting an area of the court marked with a cross - for that will give the player an instant game-over. When Gooper Blooper voleys a ball, he drops a racquet, and uses one of the different-coloured boxes by the side of him to fetch another one.

Trivia
Gooper Blooper doesn't ever miss and doesn't hit the ball like normal, he just throws it at the ball then picks another one out of the boxes around him.