Blarggs are large monsters commonly found inhabiting pools of lava in underground caverns. Originally, Blarggs resembled lazy-eyed dragons, but more recent depictions show them as being anything from blob-like beings with large mouths, arms and beady eyes to humanoid, limbed creatures. There are even some species of Blarggs that dwell in water, not lava.
Super Mario WorldEdit
Blarggs first appeared in Super Mario World as fairly rare enemies, encountered primarily in the Vanilla Dome. In this appearance, Blargg, upon seeing Mario or Luigi approach on a Skull Raft, will try to lunge at them, roaring menacingly. Blarggs could not be defeated by any conventional means for the most part and can only be avoided, though Yoshi is capable of jumping on them and, with some difficulty, eating them.
In Super Mario World 2: Yoshi's Island and Yoshi's Island DS, Blarggs themselves didn't appear, though various sub-species, such as the Gargantua Blarggs, did. These Blarggs are drastically different in appearance from their forerunner, however they attack the same way - by rearing up out of the lava when the player approaches. Yoshis cannot touch the Blarggs themselves, however they can subdue the creatures by hitting them with Eggs. These games also introduce a species of water-dwelling Gargantua Blargg known as Nep-Enuts
In Yoshi's Story, Blarggs are once again altered, being larger and given small arms, they appear in only one level, Stage 2-2: Blargg's Boiler.