What would Waluigi's special ability be in a 2D Mario platformer?

[HellJumper]

How about a kick attack?

Well, kicking is something Mario, Luigi, and Wario can also do, so it'd be weird if it was a move exclusive to Waluigi.

And I already had the idea of making him swim faster as if he had the Blue Shell, Penguin Suit, or the Frog Suit. And yes, he will be faster on foot, and will have a more powerful long jump.

But aside from his speed, jump height, etc, what would his special ability be? Should he just be skinny?

Another idea I have is if I give him the ability to go extra skinny, he can fit in those tiny pipes that the other characters would need a mini mushroom for.

 Jumping feet first into hell isn't my job; making sure it's crowded when I get there is.