An in-universe example, from Chihiro (paraphased):
"Rea can't move? Oh, it's just rigor mortis... wait a minute... Oh, Crap!, she's decaying!"
If the flashbacks are any indication, Chihiro's grandfather might have had a hand in the death of Chihiro's mother.
He didn't. However, he did zombify Chihiro's mother so she could live out her last wish, and thus Chihiro's last memory of his mother is with her as a zombie.
Not to mention wondering about what Babu has been doing behind the scenes.
