Beelzebub’s Tales About His Second Descent on to the Planet Earth—p188 notes

the destruction of various weak one-brained and two-brained beings proceeded everywhere

“… terrible custom of Sacrificial-Offerings was at that time, as it is said, at its ‘height,’ and the destruction of various weak one-brained and two-brained beings proceeded everywhere in incalculable numbers.

This is clearly not literal, since there was never a practice of sacrificing one-brained beings.