grass snake

Short definition from Wiktionary

Noun

1. 1
   A nonvenomous snake of species Natrix natrix, native to Europe, with a yellow collar.
2. 2
   A snake of either of the two species of the nonvenomous green snake, Opheodrys, of North America: A smooth green snake (Opheodrys vernalis)
3. 3
   A snake of either of the two species of the nonvenomous green snake, Opheodrys, of North America: A rough green snake (Opheodrys aestivus)