The Midnight Train Crossing

Seussical is a musical written by Lynn Ahrens and Stephen Flaherty based on the books by Dr. Seuss
The primary story is Horton Hears a Who although it ties in with other books, but Horton is the main character.
Other characters include Gertrude McFuzz and Mayzie LaBird from Gertrude McFuzz, and of course The Cat in the Hat

The entry on wikipedia is very informative. Another good place is the website of Ahrens and Flaherty

In 2005 I saw an amature production of Seussical done by the Sioux City Community Theatre.

My review of the show

My pictures from backstage at the show

My friend's pictures from the show