Continuity mistake: In the movie "Channel Chasers," when Timmy and Vicky go into Maho Mushi, Timmy gets a piece of his hat sliced off and Vicky gets the tip of her ponytail sliced off. But in the next shot, they're both back to normal.
Continuity mistake: In the TV movie, "Channel Chasers," Vicky makes herself 18, changing the shape of her body. But later there's a brief shot of her in the place where you can get into any channel, and her body's the same as it has been in any other episode. But later she goes to face Timmy and she's 18 again.
Answer: He didn't wish for it just to get more toys. He did it because he enjoys all of the Christmas experience, including his Mom and Dad being able to stay home, and not having to be babysat by Vicki.