Khandhavatta Jātaka
Khandhavatta Jātaka:The Bodhisatta was once born in Kāsi,and later became an ascetic.On it being reported to him that many ascetics died of snake-bite,he gathered them together and taught them how,by cultivating love for the four royal races of snakes -
the Virūpakkhas, the Erāpattas, the Chabbyāputtas,and the Kanhagotamas - they could prevent themselves from ever being bitten by any creature.
The story was told in reference to a monk who died of snake-bite.J.ii.144ff..cf.Vin.ii.109f.
The story is evidently an expansion of the Khanda Paritta.