From the Super Mario Wiki
“I am a Blargg, Gargantua Blargg!”
Gargantua Blarggs are massive Blarggs which resemble Nep-Enuts that reside in lava in the game Super Mario World 2: Yoshi's Island, Yoshi's Island: Super Mario Advance 3, Yoshi's Story (in which they are called Blarggs), and Yoshi's Island DS. These huge creatures attempt to block Yoshi's path by rising from the lava as the dinosaur approaches. To pass by a Gargantua Blargg, Yoshi must throw an egg at the monster's mouth. The fire creature will then sink into the lava, allowing Yoshi to continue his journey. However, they reappear after a few seconds. Also, unlike regular Blarggs in Super Mario World 2: Yoshi's Island, Gargantua Blarggs could not be defeated with POW Blocks.
In addition to Gargantua Blarggs, there are also small versions of these creatures that are seen in the game (called Kounbaba "Juvenile Blargg" in Japanese).
In the game Tetris Attack, a Gargantua Blargg appears as a ruler of the "Lava World", being allied with Flamer Guy. In here, as many other old enemies of Yoshi, was shown as a friend of Yoshi, being enchanted by Bowser to work for him. He replaces the fire fairy, Flare, from the original Japanese version of the game.
In Yoshi's Island DS, they are called Super Big Blarggs instead. Another sub-species of these Blarggs called Crusher Blarggs appear as well. These Blarggs are much taller than the Super Big Blarggs, and they can destroy dense rocks.
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