Bowser's Up air when performed after expending his double jump. The animation performed looks like a third jump of sorts and can be used to punish noobs who try to jump over Bowser. After a successful triple jump, Bowser lands and taunts.
Look at this Jiggly try to recover over my head. I'm gonna get that stupid puff ball. Jump, (predict double jump), jump, triple jump (death). fast fall, l-cancel. taunt.