Magmaargh is a subspecies of the Blaarg species. They first appeared in Super Mario Galaxy 2 where they appear in the Melty Monster Galaxy alongside the Magmaw. They are essentially larger versions of a standard Blaarg and are composed entirely of lava. They are incredibly dangerous foes as they are quite large, aggressive, and practically invincible. Magmaarghs have since appeared in various other games such as Super Mario 3D Land.
Super Mario Galaxy 2
Magmaarghs first appear in Super Mario Galaxy 2. They appear as semi-common enemies in the Fleet Glide Galaxy and Bowser's Galaxy Generator and as major enemies in the Melty Monster Galaxy. These lava monsters are seen resting in lava but as soon as Mario (or Luigi) come near, they emerge from the lava with a violent roar before washing down on him. Move whenever they do this because if they hit you, it will burn. They can also wash over platforms and phase right through them. There is no attack that can destroy or even make a dent in these lava monsters so steer clear of them. A good strategy is to get close to them, move away as they emerge and then cross immediately after they've washed down as a small delay occurs before they can wash down again. A similar variation called the Magmaw is also encountered in the Melty Monster Galaxy.
Super Mario 3D Land
Magmaarghs return in Super Mario 3D Land. In this game, they appear in World 8 and Special World 8. Unlike before (where it was possible to see their eyes sticking out of the lava) in this game, they emerge from the lava as you get close and start to travel in a straight line. Once again, they are completely invincible. The use of a Starman or an Invincibility Leaf will make you invincible to them however. A sandy sub-species of the Magmaargh called the Sandmaargh also appears in this game.
New Super Mario Bros. U/New Super Luigi U/New Super Mario Bros. U Deluxe
Magmaarghs are back in New Super Mario Bros. U, New Super Luigi U, and New Super Mario Bros. U Deluxe. In these games, they only appear during the boss fight with Iggy Koopa on his Airship. During the battle, Iggy will shoot 3 magic projectiles, one of these projectiles is red and possess a pair of eyes (similar to that of a Podoboo). If the red projectile touches the lava below, it will emerge as a Magmaargh and attempt to attack you (until coming in contact with a wall). Magmaarghs cannot be defeated during their attack. The red projectiles can be destroyed with the effects of the Ice Flower. Magmaws also reappear in this game being more common.
Super Mario 3D World
Mario Party: Star Rush
Magmaarghs return in Mario Party: Star Rush, in this game, they can be seen in the minigame Lava Labyrinth, during the minigame, players are standing on a large connected set of platforms in a lava-filled room with several Magmaarghs travelling around the lava lakes, players need to reach the largest Treasure Chest before their rivals whilst avoiding the travelling Magmaarghs, if a player is hit by a Magmaargh, they are briefly stunned which can give the competition a large advantage so be careful. Magmaarghs can phase through the mesh bridges and when they do this, players should wait for them to cross before continuing to the prize.
Mario Golf: Super Rush
Magmaarghs appear in Mario Golf: Super Rush, their first appearance in a Mario Golf game and by extension, a Mario Sports game, in this game, they appear in the course Bowser Highlands as an additional obstacle to avoid. They are seen dwelling in the lava lakes of the course alongside numerous Podoboos which can be seen hopping out of the lava. Hitting a Magmaargh with the Golf Ball will cause the Golf Ball to go right through the colossal Lava Monster.
- In several issues of Nintendo Power, Magmaarghs are commonly referred to in Male Pronouns. This implies that the Magmaarghs are the male equivalent of the lava monsters (as Magmaws are also referred to in female pronouns).