Protobothrops flavoviridis is a species of pit viper endemic to the Ryukyu Islands of Japan.

P. flavoviridis has a light olive or brown ground color, overlaid with elongated dark green or brownish blotches.

[6] Unlike most pit vipers, P. flavoviridis is oviparous and lays eggs, rather than bearing live young.

[7] To reduce the population of P. flavoviridis on the island of Okinawa, the small Asian mongoose (Herpestes javanicus), was introduced in 1910.

The venom of this species is of high toxicity, containing cytotoxin and hemorrhagin components,[10] yet the fatality rate is less than 1%.

In this case, the sake is a liquor called awamori (泡盛), alleged to have medicinal properties.