Henry is to some degree inspired by:
The Mogambo Guru
Groo the Wanderer
Henry the Octopus
Henry is a comic book character, but without the comic part, since I can't draw. Also this is not a book.
We're therefore left with "Henry is a character", except that I'm not sure he is really much of a character either.
Henry is this superhero guy.
The links below include some stories that may be read standalone. Otherwise refer to "How To Read Henry" for instructions.