Oh, VanItch. Why can't you just keep away from the Wall?
Not a chance.
This guy is way too much like Grandpa, just on the other side of the battle. And there's the problem. Because he's on the other side—the wrong side, according to Grandpa—we get a kind of biased view of him as "a very rude Zook" (42). In reality, though, we'd bet that those two aren't so different: both have national pride, both want to one-up the other, and both seem pretty blind to the consequences.
But wait a second: is it possible that Grandpa's actually the bad guy here, and VanItch is just playing defense? After all, Grandpa started it when he "snuck up and slingshotted [his] Snick-Berry Switch!" (43). Either way, VanItch is still willing to escalate the conflict. As they say, it takes two to tango, and Grandpa and VanItch dance a dangerous dance.
What's in a Name?
What kind of name is VanItch? Seusspert Ruth K. MacDonald has a few ideas:
[VanItch's] name is foreign sounding, of unspecific origin to American ears, [and] it is also suggestive of the kind of threat posed by this Zook, for he is no more dangerous or annoying than an itch, an irritation that should be tolerated rather than threatened within an inch of mutually assured self-destruction. (Source.)
Got that? VanItch is like a mosquito bite. Fantastically annoying, but not really that dangerous. Just like the bread buttering, VanItch's name indicates a difference from the Yooks… but not one that should lead to an all-out war.