Piranhacus Giganticus

A Piranhacus Giganticus is a gigantic Piranha Plant that first appeared in the game Super Mario Bros. 3.

Super Mario Bros. 3
In Super Mario Bros. 3, they only appear in Big Island. Although they are huge, a single fireball will destroy them. Despite their size, they are essentially exactly the same as any other typical Piranha Plant, other than they present a larger target and obstacle. They also appear in larger Warp Pipes than other Piranha Plants.

Super Mario 64 / Super Mario 64 DS
In Super Mario 64 and Super Mario 64 DS, Piranhaci Gigantici make their sole appearance on Tiny-Huge Island, where depending on which side of the island Mario is on they could either be tiny or huge. They also had the ability to breath fire. In this game they were referred to as Venus Fire Traps in English but still possessed their original Japanese name.

Super Mario Galaxy 2
Piranhacus Gigantici appear alongside Grand Goombas, Huge Paragoombas, and Gargantua Koopa Troopas in the Wii game, Super Mario Galaxy 2, where they appear in the Supermassive Galaxy. However, in contrast to their original appearance in Super Mario Bros. 3, they are invincible, thus serving more as an obstacle than an enemy. They can, however, be stunned with a Spin or a Star Bit, but that just hinders the player as it stops the plant from going back in the pipe.

New Super Mario Bros. U
Piranhacus Giganticus reappear in New Super Mario Bros. U. They act the same way they did in Super Mario Bros. 3 although this time need to hit with three Fireballs to be defeated, similar to Super Piranha Plants. They are found in Soda Jungle, more specifically in Jungle of the Giants, which is the only level they appear in.

Trivia

 * Piranhacus Giganticus' name could possibly be using binomial nomenclature, a scientific way of naming species having the genus name with the first letter capitalized (Piranhacus in this case) and a species name in lowercase (giganticus), both in italics. Which would result in Piranhacus giganticus.