adder
aggressive
biting
black
brown
common european adder
crossed viper
danger
dangerous
detail
european
european adder
european viper
fear
fearsome
forked tongue
frightening
herpetology
macro
mountain
nature
pain
poikilothermic
poison
poisonous
portrait
red
red eye
red list
reptile
scales
sharp
snake
surveillance
tongue
toxic
unsafe
venom
venomous
vertical pupils
vicious
viper
vipera berus
wild
wild animal
wildlife
zoology