Guffawha Ruins monster
From the Super Mario Wiki
The Guffawha Ruins monster is a stone head in Mario & Luigi: Superstar Saga, residing in the Guffawha Ruins. After Mario contracts Bean Fever, the Toad doctor tells Luigi that the cure is Crabbie Grass located in the Guffawha Ruins. The residents in Little Fungitown warn Luigi that the mission will be very dangerous, and mention the Guffawha Ruins monster, describing it as a horrible and villainous monster.
When Luigi meets the monster, the Guffawha Ruins monster is revealed to actually be nice and misunderstood; it is furious of people spreading rumors of it being a monster, so it challenges Luigi to a minigame. The Guffawha Ruins monster launches fireballs, while Luigi stands on a few moving platforms to jump over these projectiles. He has to avoid all fireballs for thirty seconds to win. If he is hit or if he falls from the platforms, Luigi has to redo it. After Luigi wins, the Guffawha Ruins monster lets him continue on his quest for the Crabbie Grass.
In Mario & Luigi: Superstar Saga + Bowser's Minions, the Guffawha Ruins monster is shown as a 3D render instead of a 2D sprite like other characters.