Petey Piranha

Petey Piranha is a giant Piranha Plant that first appeared in Super Mario Sunshine.

Super Mario Sunshine
In Super Mario Sunshine, Petey Piranha was only found in Bianco Hills. The player could defeat him if he squirted water into his mouth which makes him fall to the ground. Then, after ground pounding him multiple times while he is fallen, he is defeated. In episode 5 of the same area Petey Piranha returns in which Mario must squirt water into his mouth to wake him up and then when he is flying Mario must squirt water into his mouth causing him to gain weight and fall and Mario must ground pound him and repeat the process three more times.

There is an infamous sequence break in episode 1 in which Mario can kill the mini-boss and skip past the Shine Sprite, and take the normal path to Petey Piranha. Once you reach the part of the windmill where you the Pianta, he exclaims, "Hey, you are not supposed to be here yet!" You can take the short ride up the windmill and begin your battle with Petey Piranha.

Mario Golf: Toadstool Tour
Petey made his first appearance in a spin-off game in Mario Golf: Toadstool Tour. In this game, he was an unlockable character, obtainable by completing all side games (excluding the Birdie Challenge) on beginner, intermediate and expert. His large size made him the most powerful golfer in the game, capable of hitting the longest distance and launching the ball with a higher trajectory than any other character. When he hits the ball with his club, a golden streak follows the ball, like the tail of a comet. Like the other unlockable characters, his star character was available from the start.

Mario Kart: Double Dash!!
Petey Piranha is a character introduced to the Mario Kart series in Mario Kart: Double Dash!!. Petey is a Heavyweight character, meaning that his choice of karts tend to have a high top speed and traction, but poor acceleration and handling. In Double Dash!!, his default kart is the Piranha Pipes and his default partner is King Boo. He can use any special item, along with King Boo. Win the Mirror Star Cup to get him.

Mario Power Tennis
Petey is an unlockable character. He is the most powerful character in the game. His power shot uses the goop seen in Sunshine. Petey Piranha can be unlocked if the player finishes the thunder and fire tournaments in doubles.

New Super Mario Bros.
Petey Piranha appears in the last castle of World 5. The player can defeat him when his ground pound misses and ground pounds his head or belly. If Mini Mario defeats him World 7 will open.

Super Smash Bros. Brawl
Petey Piranha appears as the first boss you fight in the Subspace Emissary mode. After Mario is blasted by the cannonball, Petey appears and kidnaps Princess Zelda and Princess Peach in cages. Kirby then has to attack the cages in an effort to free the Princesses, however, only one can be saved, the other is turned into a trophy by Wario. In the Great Maze later in the game the player must face the 7 previous bosses and the first one is Petey Piranha.

Mario and Luigi: Partners in Time
Princess Shroob had Petey Piranha devour Princess Peach in a stadium. Mario, Luigi, and their baby selves then rush into the stadium and try to save Princess Peach by following the creature. However, one of their friends who rushed in before, Kylie Koopa, an ace reporter who is rather impulsive, is swallowed by Petey as well! In the end, Mario, Luigi, Baby Mario, and Baby Luigi manage to defeat Petey and save Kylie and Peach. Petey has a certain weakness against fireballs, possibly because of his flammable nature as a plant.

The First Fight
In the past of Mario & Luigi: Partners in Time, Petey Piranha ate Princess Peach and Kylie Koopa in the Koopaseum "basement". Mario, Luigi, Baby Mario and Baby Luigi went into the Gritzy Caves and fought him to save Peach and Kylie. Petey's attacks include diving into the sand and making rocks fly towards the Mario Bros.; to dodge this assault, the player must look at how Petey dives and jump with the according Bro. The mutant plant starts the battle hovering, but after so many attacks, he falls into the sand. While in this state, only his head is visible above the ground. His other main attack, while grounded, includes going underground and swallowing the sand, trying to drag the Mario Bros. into his mouth. The brothers must jump up and down as to not get consumed. After a certain number of turns, he jumps back out of the sand and resumes hovering. He can, once again, be knocked out of the air. It should also be noted that while Petey does appear in the past, he may not be from it, and the Shroobs may have brought him from the future to aid in their conquest of the Mushroom Kingdom.

Battle in Bianco Hills
In Super Mario Sunshine, Bowser Jr. selected Petey to help him defeat Mario on his vacation to Isle Delfino. Petey Piranha was stationed in Bianco Hills where he terrorized the residents. When Mario faced him on top of the Big Windmill, Petey Piranha's enormous weight made the windmill's roof collapse and he and Mario fell into the windmill. Inside, Petey Piranha attacked Mario by spitting Goop at him. Mario, however, shot water into his mouth with F.L.U.D.D., and then Ground Pounded Petey Piranha's belly three times. Petey Piranha then dissolved into Goop.

However, Petey Piranha survived and appeared once again in Episode 5, where he was happily snoozing on a cliff high above Bianco Hills. After Mario woke him by blasting him with a Poink, Petey Piranha used his enormous arms to fly, and launched an attack from the sky. Mario had to get him on the ground by shooting Poinks at him, and once again had to fill Petey Piranha's belly with water and Ground Pound it. On the ground, Petey Piranha not only attacked by spitting Goop, but also by unleashing small tornadoes. After being defeated, Petey Piranha once again dissolved into Goop and is not seen again in the game.

Petey Piranha Returns
Even if he was said to be defeated, Petey Piranha reappeared as a boss in Super Princess Peach, defending Bowser's Villa from Princess Peach, and keeping a Toad hostage. In this game, he is labeled under the name Boss P. Plant. When Peach sees Petey, the overgrown plant swallows the Toad, who is trapped in a ball, and the princess must defeat Petey to rescue the poor mushroom resident. Peach had to use her Gloom vibe to make a plant grow so that she could leap on a leaf and once again use the vibe to put tears into the plant and inflate him, making him fall down and reveal his weak spot: his belly button. Peach had to jump on his belly five times to defeat him. The method of defeating the plant makes this appearance quite similar to his Super Mario Sunshine appearance.

Petey Piranha in the Ice World
In New Super Mario Bros., Petey Piranha was the boss of World 5, the ice world. He attacked by flying up high, then dropping from the sky, crushing any opponents beneath him with a move similar to the Ground Pound. Since the floor was made of slippery ice, after attacking he slipped and fell. It was then that he could be attacked. If Mario or Luigi could defeat him using a Mini Mushroom, they would travel to World 7 instead of World 6. While tiny, the brothers were forced to use Ground Pounds to simply hurt the beast. Many Piranha Plants appeared in Petey's castle, a subtle hint that he would appear as the boss.

Trivia

 * Dino Piranha from Super Mario Galaxy greatly resembles Petey Piranha.
 * Although Petey Piranha isn't in a Mario Party game, before they made Wiggler's Garden in Mario Party DS, they where thinking of Petey's Greenhouse. The story was that one of the Piranha Plants have betrayed him.
 * In Super Mario Sunshine in either of the missions that you face Petey Piranha if you time a ground pond just right when he is down you can glitch the physics engine and you will be inside of his belly.