Possible Clues:

• Creator of Sam-I-Am
• Doctor whose publications are read mostly by children
• 'There's a Wocket in My Pocket!' writer
• Grinch-creating Dr.
• Sneetches' creator
• Geisel pseudonym
• Dr. who created Horton
• ''Yertle the Turtle'' byline
• Noted trisyllabic metrist
• ''The Cat in the Hat'' author