Possible Clues:

• Creator of the Grinch
• Creator of the Lorax
• 'The Cat in the Hat' writer
• "Green Eggs and Ham" author
• Writer born March 2, 1904
• 'Oh Say Can You Say?' author
• Devotee of anapestic tetrameter
• Creator of the Zax
• Yertle and Lorax creator
• ''There's a Wocket in My Pocket!'' author