blood feast
/ˈblʌd fiːst/noun
1An occasion of extended or unrestrained violence and bloodshed; a war or massacre.
2A feast of blood or flesh, especially that of a person killed as part of a ritual or occult practice.
3An instance of feeding on the blood of a person or animal by a mosquito, leech, etc.
Origin
Early 17th century; earliest use found in George Chapman (?1560–1634), poet and playwright. From blood + feast.