Who is Dennis in The Pigman?

Dennis Kobin
is a friend of John and Lorraine.  He is usually paired with Norton Kelly, and the two are
described as "demented", and are always causing trouble.  Of the pair, Dennis is the
follower, and is nowhere near as malicious and conniving as the more assertive Norton.  John
says that Dennis is "not very bright", and notes that "he talks so slowly some
people think he has brain damage".  Dennis does hold the record for the being able to
engage a stranger in the longest conversation ever in a "phone marathon" game that the
four teens have created.  The object of the game is to call a number at random and see how long
one can keep the person who answers on the line.  Dennis once called a lonely old woman and made
up a story about needing advice about how to treat a skin disease which he had as a result of
having had his nose bitten off by a rat when he was a baby.  He was able to keep the woman on
the phone for well over two hours.

Dennis's father works long hours and
drinks a lot.  When his mother is not home, the group sometimes gathers at his house to play the
phone marathon game (Chapter 3).  When John and Lorraine decide to throw a party at the Pigman's
house, they invite Dennis, but caution him not to tell Norton because they know that Norton will
take the opportunity to steal from the Pigman, and otherwise cause trouble.  Dennis, however,
can be counted on to be discreet and to follow instructions.  Because John has asked him to,
Dennis steals some alcohol to bring to the party from his father's whiskey cabinet, and supplies
some soda mixers and glasses from his house as well (Chapter 13).