Os marcianos alternativos de Bertram Chandler.
Para escolher alguns dos pontos da sua pergunta, veja o sabor dos humanos selvagens:
Wilkinson took advantage of the short silence to ask a question. "Why did the Masters go to all the trouble of invading Earth?"
"To begin with, we do not make good slaves. Secondly but perhaps most important they don't like the taste of us. Although they have come to prefer the flavor of the wild ones, Bill's people, to that of their human cattle."
A referência às canetas de engorda é:
"So, Vanessa Wilkinson, you are his wife. That would account for the zeal with which he protected you from Mr. Talbot and his squad. Please do not think that I bear any malice; on the contrary. I had already reached the decision that Mr. Talbot was to be transferred to the fattening pens as an inmate, not as a guard. After all, we must tread delicately; we must, as it were, go through the motions of being faithful and docile slaves of the Overlords, even though ... But no matter."
Eu não encontrei nenhuma referência para drenar sangue.