Petey Piranha

Petey Piranha is a recurring antagonist in the Super Mario series. His first ever appearance was in Super Mario Sunshine.

Super Mario Sunshine
In Super Mario Sunshine, Petey appears in two missions on Bianco Hills. The first mission he is in, Mario has to navigate himself to the top of the windmill to squirt water in his mouth when he tries to spit out gunk, causing him to swell so much that falls. When he falls his belly button will be sticking out and Mario must ground pound it three times. In the other mission, Mario must squirt water in his mouth, waking him up. He will then fly around, and Mario must squirt water in his mouth so he falls and Mario must then ground pound him.

New Super Mario Bros.
In New Super Mario Bros., Petey Piranha is the final boss of World 5. Mario defeats him by ground pounding him when he trips on the ice floor. Defeating him unlocks access to World 6. If Mini Mario defeats him, World 7 unlocks instead.

Mario Pinball Land
Petey Piranha appears in this games as the first boss. His appearance is slightly different in this game, with his neck longer and his mouth more outward.

Subspace Emissary
Petey Piranha is the first boss in the Subspace Emissary of Super Smash Bros. Brawl. He captures Peach and Zelda and puts them in a cage. Kirby must destroy one of the cages to defeat him.

Super Smash Bros. Ultimate
Petey Piranha appears as the Final Smash of the Piranha Plant fighter. Piranha Plant summons him in fight, where he thrashes the cages he held in Brawl across the stage.

Mario & Luigi: Partners in Time
In the Mushroom Kingdom's past, Princess Peach is sentenced to be fed to Petey Piranha in the Koopaseum by Princess Shroob's orders. Shortly before the execution, Mario, Luigi, Baby Mario, and Baby Luigi enter the Gritzy Caves beneath the Koopaseum to find Petey and save Peach, while also encountering Kylie Koopa, who two Shroobs have suspended by a rope. Petey then emerges from the ground and the Shroobs cut Kylie's rope, feeding her to Petey as well as the princess. But before the Mario Bros. can do anything, he burrows away. They later encounter him in the Gritzy Desert as the game's third major boss. Once defeated, Petey Piranha explodes and both Kylie and a Cobalt Star Shard fly out of him, but Peach does not. Kylie explains that when she was eaten, she saw the princess, but Petey spat her out right after swallowing Kylie.

Mario & Luigi: Paper Jam
Petey Piranha and his Paper counterpart appear in the game as the first and fourth boss respectively. In the first fight against regular Petey Piranha, he will try to grab and eat Mario, Luigi, or Paper Mario, but by jumping at the right moment, he will spin around and fall over, with his unprotected belly being his weak spot. When Petey's health reaches halfway, He will try to spit goop at the Mario brothers, but he can be outran using Paper Mario's airplane mode. Paper Petey Piranha fights similarly, except he steals Paper Mario's Copy ability to make clones of himself. When enough damage is dealt, the copies drop on the floor. Only the true Paper Petey Piranha will take damage, which it signals by lifting its head.

Paper Mario: Sticker Star
Petey Piranha is one of the five monsters empowered by a Royal Sticker that came from the Sticker Comet. He gained its power by eating it from a Shy Guy tribe and hid out in Rumble Volcano in World 5. When Mario arrives at the volcano, Petey Piranha eats Kersti, preventing Mario from Paperizing. When he fights Petey, Mario must avoid Petey's attacks and once Petey gets dizzy and trips, he must then bounce on his belly to free Kersti and defeat Petey.

Paper Mario: Color Splash
Petey Piranha appears in the game as "Petea Piranha", as he emerged from the Teapot thing in Plum Park. According to the manual, two Sniffits stuffed Petea into the shape of a teabag into the teapot, which poisoned the water. If Mario attempts to jump on Petea Piranha, he will counter the attack by swallowing Mario, damaging him in the process. However, Mario can hit him with a hammer when he is stunned or use the Lemon Thing Card to make him soggy and fall, leaving him vulnerable to jump attacks.

Mario Party 10
Petey appears in Mario Party 10 as the boss of Mushroom Park, in the boss minigame, Petey's Bomb Battle. The contestants must throw bombs at him. He can swallow them and shoot the back.

Mario Tennis Aces
Petey Pirhana appears as both a boss and a playable character in Mario Tennis Aces. As a boss, you fight him in the Forest Monster mission, where you must defeat Petey Piranha within 300 seconds. Every time Petey Piranha rallies the ball, he loses a bit of health, and when he loses a full meter,he falls down with his belly-button exposed. You then must aim a Zone Shot at said belly-button, to damage him further. He also sends out tornado's, which Mario has to avoid or jump over. As for his playable role, he was announced on September 13, 2018 in a Nintendo Direct. He is set to be released (along with Paratroopa, Diddy Kong, Birdo, and Shy Guy) on September 19, 2018 as a part of the 2.0 update.

Trivia

 * Dino Piranha from Super Mario Galaxy and Peewee Piranha from Super Mario Galaxy 2 look similar to Petey Piranha.