For those that aren't familiar, the Necronomicon is a super scary book imagined by H.P. Lovecraft. The neko version would be a fair bit less scary, as we see. It would also make Neko Atsume way too easy. Trevor and Gerald are not to be confused with Casper and Charlie. They're much smaller! Update: Of course, the author of the Nekonomicon is H.P. Lovecat.