The Krevslap combo is a Brawl combo discovered by Krevin in July of 2008. In theory, this combo can be used in all three Smash games, but in Super Smash Bros. and in Melee, almost all of the cast is able to DI out of the combo.
The combo is executed by performing Yoshi's Dash attack, then his two-hit Neutral attack, then his Dash attack again. The opponent is carried off the stage, making them vulnerable to Yoshi's Forward aerial meteor smash.
This combo cannot be performed on all characters, and can only be performed at certain damages. The name of the combo is a portmanteau of "Krevin", the discoverer, and "slap", which references the slapping motion that Yoshi's head makes during his Forward aerial.
While experimentation is currently being done to see exactly what range of damage each character may be in for this combo to be performed, a few characters have been proven immune to this.
The following characters are simply too light to be susceptible to this combo:
The following characters can be affected by the combo at 0% damage, but are capable of escaping with DI:
The following characters are too heavy to be susceptible to this combo at low damages, and at higher damages it becomes more reasonable to fight them without the Krevslap combo:
All other characters can theoretically be fought with this combo, though it may be possible to break out of it with some of the lighter characters.