Horrors of the Z'Bri is a 1999 role-playing game supplement for Tribe 8 published by Dream Pod 9.
Horrors of the Z'Bri is a supplement which focuses on the past and present of the beings known as the Z'bri.
[1] Horrors of the Z'Bri was reviewed in the online second version of Pyramid which said "The Z'Bri are the third part of the triumvirate of groups around which Tribe 8 is based.
They don't eat flesh or drink blood (well, not all of them).
They're extra-dimension entities of spirit who came to Earth to experience the pleasures of the flesh.