A blessing upon all living beings!
A. Canonical version.
Vinaya ii. 109-110.
Now at that time a certain monk was bitten by a snake and died. They reported that fact to the Exalted One.
Assuredly, monks, that monk had not suffused the four royal families of snakes with friendly thoughts. For, monks, if that monk had suffused the four royal families of snakes with friendly thoughts, in that case, monks, that monk would not have been bitten by a snake and died.
What are the four royal families of snakes?
The Virūpakkhas are a royal family of snakes.
The Erāpathas are a royal family of snakes.
The Chabyāputtas are a royal family of snakes.
The Black Gotamakas are a royal family of snakes.