First off, despite the title this is not a zombie book. I know, it fooled me too. The book is instead a semi-humorous, semi-auto-biographical account of the writer's life, with most of the story taking place in England around the year 1850. The heart of the book is the struggle of the author to break from his parents and from the path to priesthood that they had set him on. This part is regularly interspersed with jokes, stories, philosophical tangents, and a general happy cynicism, and overall it works well. It's not quite Jeeves, or Three Men in a Boat, but for something written in 1850 it is surprisingly readable and enjoyable. I would snort and/or lol every 3-5 pages or so, and you feel for the guy, his terrible childhood, his misplaced idealism, and his willingness to lay out some truly embarrassing scenes of himself. The actual institutions he is criticizing are mostly discredited and gone now, so you miss some of the original impact of the book, but it is still enjoyable to read and the story makes familiar a somewhat unfamiliar time and place.
The heart of the book works well, but the appendages not so much. The first ~50 pages are fairly dull, as the author tells the story of the previous 2 generations of his family. There are only a few bright spots here, mostly about his parent's awkward courtship and marriage. The last ~80 pages are also lackluster. At this stage of the writing he lost the editor who had helped him with the rest of the book, and it really shows. The humor mostly goes missing, and rather than being a description of bad things happening to him, it becomes description of the author being an asshole once he comes into his money and freedom. He becomes unhappy with his wife, and then happily finds a reason to annul their marriage and put her back on the streets. He is unhappy with his entire family, so he breaks with all of them. He certainly doesn't want to raise his kids, so he ships them off for someone else to take care of. Literally, he is walking in the park, sees a working class family that seems cheerful, and he hands his kids and a stipend over to them. Parenting complete for the next 10 years! This part I actually liked, since it helped explain to me the British habit of avoiding their children (e.g. Churchill and his parents). At least in the author's case, the reasoning was that he was made miserable and hostile by interacting with his parents, so there's no need to repeat the process with his own kids. Instead he simply provides for them and tries to put them in a decent place to develop. Once he's taken care of all the family tasks, the author then sits back and spends the rest of the book living a life of leisure on top of his massive stacks of cash. Ok, I can't really fault him on that point. :)
In summary, the book isn't bad reading and it has aged fairly well, but it's not the deepest thing or the funniest thing that has been written.