The term anthropophagi (cannibals) may refer to one of the following:

Creatures from English folklore with no heads and a mouth in their chests. Their diminutive brain was located in their groin, and their eyes on their shoulders. While they were made widely known by William Shakespeare in Merry Wives of Windsor (1602) and Othello (1605), they were not created by Shakespeare, and indeed were mentioned as early as the 5th century BC in "the Histories" by Herodotus as Androphagi.

The name given to primitive Christians by others. This usage appears in Tertullian, in his Apologeticus (ch. VII), and Salvian (de Provid. Lib. IV). They affirmed that the Christians, in the mysteries of their religion, killed a child, and feasted on its flesh. This was grounded on what they had heard of the Eucharist.

References

Greek legendary creatures | English folklore | Ancient Roman Christianity