Gooper Blooper is a large Blooper first met in Ricco Harbor in Super Mario Sunshine. He is the second boss fought in the game.
Super Mario Sunshine
Gooper Blooper is encountered when Mario pulls off his tentacle in the crate. Gooper Blooper starts the battle using his tentacles to attack Mario. His weakness is to pull his snout. Gooper Blooper will get angry for squirting water at him with F.L.U.D.D or pulling his snout. Gooper Blooper also spins to wipe Mario out of his arena. It will be difficult to beat him without pulling his tentacles, so it is recommended to do so. Gooper Blooper will later spray ink after pulling his cork at Mario, so it means that he must avoid this attack. Gooper Blooper will spray more ink which will damage him, so Mario must pull his snout and finish the battle.
Gooper Blooper later appears in Noki Bay and the fourth episode of Ricco Harbor.
Super Princess Peach
Gooper Blooper later appears as the fifth boss of Super Princess Peach. Princess Peach must avoid the ink shot from its snout and then attack its tentacles. First, she must avoid it or this will launch her in the air. Like in Super Mario Sunshine, his weakness is his snout. Gooper Blooper will calm down after death. Princess Peach must pop his bubble and then his snout.
Paper Mario: Sticker Star
Gooper Blooper appears as a boss possessed by the Purple Royal Sticker. Due to the Royal Sticker, Gooper Blooper has poison attacks, unlike in the other games. The music will change when he changes the dancing with its tentacles. He will turn fully purple after a while. At that moment, using a Sponge Sticker will reflect the toxin Gooper Blooper shot out and poison him instead.