From the Super Mario Wiki
Chap is an inhabitant of Flipside who appears in Super Paper Mario. In the PAL version of the game, this character is called Glim. The word "chap" is a slang term for a male person, and is used for another character as well, who is also from the same game. This may in fact be riffing on the fact that everything this Chap thinks of has either already happened, or (in terms of literacy) has been taken, including his own name. This Chap's counterpart in Flopside is the ever-lovesick Slim.
Chap can be found on the second floor of Flipside. He greatly enjoys peace, commonly ranting on Flipside's enjoyable prosperity. As the game progresses, he eventually grows tired of peace, wishing for more out-of-the ordinary events to happen; coincidentally, every "unusual" event he thinks of has already happened to Mario and the other heroes, occasionally even in "peaceful" Flipside itself. By the end of the game, he returns to his typical lines about loving peace, claiming shortly afterwards that he still does find peace "all you can really ask out of life". Chap is additionally stated by Tippi and Tiptron to have dreams of becoming an author, but all of his book ideas have apparently already been done.