This strange character in Twain's text is certainly an intriguing character, but it is clear that he is neither a "Pudd'nhead" as he is called nor a genius. It seems instead that he is merely something of a misfit, a character who doesn't really fit in to the society around him because of his quirks and his idiosyncrasies. It is of course his prints that help solve the mystery of what happened with Roxanna and her child and the master's child, but this is shown to be more of a result of luck, as Pudd'nhead Wilson only realises the truth as a result of the prints that he took so long ago and also a dream that he has. He is a character, however, who has significant wit and intelligence, even though this is not understood by those around him. Note the following entry in his personal calendar:

Behold, the fool saith, "Put not all thine eggs in the one basket" - which is but a matter of saying, "Scatter your money and your attention"; but the wise man saith, "Pull all your eggs in the one basket and--WATCH THAT BASKET." 

This is clearly a very humorous truism, and it is typical of the kind of humour that Pudd'nhead Wilson displays. In conclusion, he is neither a genius nor a dunce, but is something of a misfit who is not understood by those around him in society.