viper

noun

1. A venomous snake in the family Viperidae.
2. (informal)Any venomous snake.
3. (figuratively)A dangerous, treacherous, or malignant person.

   “And aggravate my folly who committed / To ſuch a viper his moſt ſacred truſt / Of ſecreſie, my ſafety, and my life.”

   “Consider, for the love of Heaven, to what you run madly: will you take this viper into your bed?”

   “Then there's the heterosexual, open-mined ^([sic]) entourage who loves us dearly and are our best friends. They laugh at our humor and understand our sorrow. For they are rare and unique in prison. But the vipers always ruin things. They refer to our straight friends as "Closet-Cases," "Undercovers," and "Flip-Floppers."”

4. (slang)A person who smokes marijuana.

   “Dreamed about a reefer five feet long / Mighty Mezz, but not too strong / You'll be high but not for long / If you're a viper”