Lionel Cosgrove is a timid, clumsy young man who is wrapped around his demanding Mother's finger. When he decides to go to the zoo with pretty young shop girl Paquita, his jealous Mother is bitten by a Sumatran Rat Monkey and turns into a ravenous zombie. Lionel looks after her (and all the others she turns into zombies), pretending nothings wrong and giving up his Mother's estate to his greedy Uncle Les in desperation. However, when the zombies break loose, it's up to Lionel to put the zombies in their place and rescue Paquita.