From my zombies-in-Canada work in progress:
…The preferred term for those that have undergone the transformation in question is “revenant”. The word revenant should not be capitalized.
Unless you are directly quoting a source, do not use the pejorative terms “zombie” or “undead”. Both these terms carry a substantial semantic payload. If they are used, make it clear that they are terms used by the quoted source, and not terms normally in use by your outlet. In extremely revenant-friendly regions (Moose Jaw and environs, for instance), you may wish to consider using asterisks to mask the term: “z****e” or “und**d”, for example.
—Canadian Press Stylebook, 23rd Edition (2017)