The narrator in The Cat in the Hat Comes Back is a total stress-case. And that, dear Shmoopers, means that the tone is just as stressed:
Then we saw the cat wipe
The spot off the dress.
Now the dress was all clean.
But the wall! What a mess! (97-100)
Our heart-rate is rising just read the nervous narration. You'd think the Cat's goofy shenanigans would make things a little more light-hearted, but the panicky attitude of the narrator just seeps into our brains and we can't help but freak out a little right alongside him.