A "Seussical" lyricist collaborated with Stephen Flaherty on a musical based on a screen play written by which person?
Lynn Ahrens:  Together with Flaherty, they have written many musicals, including "Lucky Stiff", "Once on This Island", "My Favorite Year", "Ragtime", "Seussical", "A Man of No Importance", "Dessa Rose", "The Glorious Ones", and most recently seen on Broadway, "Rocky the Musical". Rocky the Musical: Rocky the Musical (originally Rocky: Das Musical) is a 2012 musical with music and lyrics by Stephen Flaherty and Lynn Ahrens, with a book by Thomas Meehan, adapted from a screenplay by Sylvester Stallone.
Sylvester Stallone