Which Dr. Seuss character was featured on the author's car license plate?

Theodor Geisel (1904-1991), also know as Dr. Seuss, saw his first children’s book published in 1937. ‘And To Think That I Saw It On Mulberry Street’ was rejected 27 times before finally being accepted. Geisel was about to throw the book away, when he ran into a former classmate, Mike McClintock, who had just been appointed juvenile editor of Vanguard Press; McClintock snapped it up.

For many of us, our earliest recollection of a Dr. Seuss book is probably not ‘Mulberry Street’, but ‘The Cat in the Hat’, which was published some 20 years later, in 1957. At that time, boring school primers were said to be a major cause of children not wanting to read; Seuss wrote the book in response to his publisher’s challenge to “write me a story that first-graders can’t put down.”

Some have theorized that Geisel (1904-1991) published ‘The Cat in the Hat’ as a bit of a self-portrait. However, that children’s classic book was released the same year as another all-time great in the Seuss canon: ‘How the Grinch Stole Christmas!’

Geisel apparently identified with the grumpy character (who initially hates Christmas but then has a change of heart) to such a point that he had a customized license plate on his Buick that read “GRINCH”. (Perhaps ‘Cat in the Hat’ wouldn’t fit on the plate.)

*Geisel also wrote books as “Theo LeSieg” (LeSieg being Geisel spelled backwards). In researching this subject, I learned Geisel wrote, but did not illustrate, the books published under that pseudonym.