Peter Jackson – Dawn of the Dead (1978)
"If you know nothing about Peter Jackson’s career before Lord of the Rings, this might not seem like the obvious first pick.
But if you know that Peter Jackson actually started his career making some of the goriest/nastiest horror-comedies ever made (his film Dead Alive AKA Braindead set a record for the most fake blood ever used on a film set, only beaten in 2013, nearly two decades later), this pick makes perfect sense."