I've just finished reading Pontypool Changes Everything, the book on which the movie Pontypool was (ostensibly) based. To say that the makers of the movie took liberties with the book would be like saying that Picasso's cubist work took liberties with proportion and perspective. The protagonist of the movie appears in one or two chapters in the last third of the book, never sits down in a radio station, and ends up pretty thoroughly dead about as quickly and uneventfully as he was introduced. The rest of the book is a nightmarishly squirrelly trip through the minds of assorted doomed people on the peripheries of a new plague that pretty much razes the human population of a chunk of Ontario. Yes, people eat each other and yes, it seems to be spread through language, but otherwise it has as much in common with the movie as Rosencrantz and Guildenstern Are Dead did with Hamlet.
I mean, we're talking pissed-off babies cutting their own umbilical cords and going to live with other babies at the bottom of icy lakes, brothers and sisters catching and eating zombies after being abandoned by their parents, sex addicts personifying their Higher Power as a separate being who talks to them, and damn near the first third of the book is the story of the first guy to spot one of the plague victims, and the plague itself doesn't make an appearance until a few chapters in.
It's sort of a challenging read, is what I'm saying.