Naval Piranha

"You fools! Do I have to teach you penalty for removing the spell? You get to come for supper... MY supper!!"

- Naval Piranha

Naval Piranha is a recurring Piranha Plant boss. She started out as a normal Piranha Plant, but was altered by Kamek's magic during the events of Super Mario World 2: Yoshi's Island. She grew to gigantic proportions, with long thorny stalk and two secondary Naval Buds. As her name suggests, Naval Piranha inhabits the water. In battle, she spits out Nipper Plants; it is unknown if they could grow into large, water-dwelling plants like Naval Piranha.

Another Piranha Plant boss that is similar in appearance to Naval Piranha appears in Paper Mario. It is called Lava Piranha, and in accordance with its name, it inhabits lava instead of water.

Super Mario World 2: Yoshi's Island/Yoshi's Island: Super Mario Advance 3
Naval Piranha is the boss of World 3 in Super Mario World 2: Yoshi's Island, and reprises the role later in the GBA remake. After being magically enlarged and enhanced, she battles the Blue Yoshi, who throw eggs at her only weak point which is her large and bandaged belly button (with the "X" band-aid). After being hit with enough eggs, Naval Piranha is defeated.

A famous trick, exclusive to only this boss, is that Yoshi can beat her before the fight even starts. If Yoshi stands on the very edge of the ledge Naval Piranha is rooted to (or jump from the water and aim) without triggering the scene, he can simply throw an egg at her "unmodified" form to defeat her in one hit. A surprised Kamek then approaches, shouts "OH, MY!!!" and flies away, thus Yoshi clears World 3.

Tetris Attack
In Tetris Attack, Naval Piranha, allied with her Naval Buds, is in the tenth level and the last boss of Easy Vs. mode. She appears in place of the Dragon from the original game, Panel de Pon.

Yoshi's Island DS
During the introduction to Yoshi's Island DS, Naval Piranha makes an appearance alongside the other castle bosses in the game as the events of Super Mario World 2: Yoshi's Island are recapped.

Yoshi's Woolly World
"Wake up, Naval Piranha! It's supper time! The main course is Yoshi! Bon appétit!"

- Kamek

Naval Piranha reprises the role of a boss in Yoshi's Woolly World, in this case being the boss of World 4. After being enlarged by Kamek's magic, the monstrous plant jumps to a pipe in the background, and calls forth her Naval Buds. Shy Guys will then throw bombs at the foreground; which Yoshi must swallow and spit out at the mutant flower's open mouth, causing her to swallow the bomb and reveal her weak spot: her belly button. Yoshi must ground-pound it to deal damage. Then, the Naval Buds will create a series of attacks that Yoshi must avoid. Repeating the process two more times will end the boss battle.

Similar to Super Mario World 2: Yoshi's Island; Yoshi can throw a Yarn Ball at the sleeping Piranha Plant before triggering Kamek's appearance. This causes a slightly different scene, but Naval Piranha cannot be skipped and must be fought this time in order to progress to World 5.

Naval Piranha reappears in level 4-S, where she chases Yoshi through an auto-scrolling level. Yoshi can throw a Yarn Ball at Naval Piranha to make her disappear temporarily, though this does not stop the auto-scrolling and she will reappear after a few seconds. It is unknown whether this is the same Naval Piranha as the one fought in the boss level, as she has red vines as opposed to the boss' green vines. If she is able to gobble up the Yoshi while he is moving through the level, he will be instantly defeated.

Naval Piranha also reappears in the Boss Tent. She is fought the same way; however, she attacks faster making it harder to hit her.

Mario Party Advance
Naval Piranha makes a reappearance in Mario Party Advance. At the Bowser Lab, choosing to see the "scary monster" unveils Naval Piranha. Afterward, Bowser has the player face her in the minigame Koopa Kurl. After winning, the player gets to keep the minigame. The end of game credits say she now lives and thrives in the desert.

Trivia

 * Naval Piranha's name has a double meaning, referring both to her aquatic area and the large belly button she grows, i.e. her navel.
 * Naval Piranha and Raphael the Raven are the only world bosses in Super Mario World 2: Yoshi's Island to use the extended variation of the boss theme.
 * Not including Baby Bowser, Naval Piranha is one of the only two bosses from Super Mario World 2: Yoshi's Island that make an appearance in Yoshi's Woolly World, the other being Burt the Bashful.
 * The official English website for Super Mario Advance 3 misspells her name as "Naaval Piranha".