There is no dought (i cant spell) in my mind that mulluck is alive. And i have a couple of reasons.
1.He is never confimede dead.
2.This is a qutoe from MO's instruction guide. Note the words in capital."Future games of the Oddworld Quintology introduce new dilemmas, new villans, and most importantly new and unlikely heros like Abe and Munch. BE FOREWARNED: THE INHABITANTS ALL LIVE ON ODDWORLD TOGETHER, AND AS THE STORY UNFOLDS, CHARACTERS THAT ARE OVERLOOKED COULD PROVE REALLT IMPORTANT IN THE BIG PICTURE.
3.If that is in Mo's guide it is probably pointed to the first 3 games and mullock has been overlooked. I also believe somting will happen to oddworld.