Thunder Sass is a small Hooraw that wears yellow clothing. He also has an angry expression on his face.
During his battle, the Thunder Sass is the least balanced (in contrast to the Heavy Zest), having the highest speed and power (in contrast to the Sorrow Fist), but the lowest defense and stamina.
The battle conditions for Thunder Sass is that Mario can only win by counterattacking and can only heal during his turn.
- Hooraw Charge: Thunder Sass will bounce off of the group of Hooraws and into Mario. Mario must have his hammer ready to counter this attack, AND he has to face in the right direction. The Big Massif also uses this move during his battle.
- Charging Fist: Thunder Sass will dash at Mario attempting to punch him. Mario must jump at the right moment in order to damage him.
Since Mario can only heal and counterattack, Mario must try his best to counterattack all of Thunder Sass' attacks and heal when necessary.
- "SO SLOW! You made me wait forever! I'll crunch you with just my abs!"
- "You guys are so not buff... I bet you even eat carbs!"
- "SASS TIME! But first... some cardio! (Runs around the perimeter of the room)"
- "I'm gonna teach you punks some manners!"
- "Not so sassy now, are ya?! Come back when you want more!"
- "I can tell you lift...a little bit! But now I'm hitting rage mode!"