Every verse and image parodies a Dr. Seuss book with one letter in the title changed:
One Fish Two Fish Rad Fish Blue Fish
Oh, the Planes You'll Go!
The Cat is the Hat
Horton Watches the Egg
Foe in Socks
If I Ran the Cirrus
Hunched in Bunches
Green Ergs and Ham
The Better Battle Book
Oh, the Thanks You'll Think!
Mop on Pop
The Soot Book
The answer is therefore DREAMS.