Yeah, the fat kid has a stupid advantage with that koala card tho, I cant think of a card that can defend against it. If he pulls it early you better hope you have a trap or effect of some sort or fuxxored.
Later in a match with the deck you start with a water monster charged with the starfish guy, the water umi, and/or that shell might prove somewhat of a match but its tough to say.
Really just gotta get lucky with a trap card or lure him into a set monster that has a crippling effect.