At the risk of saying the obvious, switched identities were an on-going
preoccupation for Twain.  Yes, there's a great deal of it in
PUDD'NHEAD WILSON, but:

--Both A CONNECTICUT YANKEE IN KING ARTHUR'S COURT and THE PRINCE AND
THE PAUPER are so involved in identity games that their very titles
reflect it.  I'm thinking not only of Hank Morgan's basic jump in time,
but also of the long episode in which the Boss and the King travel as
common men, then are turned into slaves.

--Or take HUCKLEBERRY FINN.  Huck plays a girl.  He is "George Jaxon" at
the Grangerfords.  He is the English valet of the purported Wilkes
brothers.  He claims to be Charles William Albright in the "raftsman
passage."  He is Tom Sawyer in the long final section.  And in brief
passages he invents several other identities for himself (for instance,
when he talks the ferry pilot into looking for the "remainders" of his
relatives on the Walter Scott).
        Meanwhile, Tom passes the last chapters as "Sid Sawyer," the
Duke and King take on all sorts of identities, and even Jim gets
disguised as "old King Lear and a dead A-rab."

I have trouble believing there are more identity shifts and perception
games in PUDDN'HEAD than in HUCKLEBERRY FINN.

Mark Coburn