adder
aggressive
animal
beautiful
berus
black
closeup
common
common european adder
contrast
creeping
crossed
crossed viper
danger
dangerous
detail
endangered
european
fear
fearsome
frightening
gray
grey
herpetology
macro
male
mountain
nature
pattern
poikilothermic
poison
poisonous
reptile
scales
scary
snake
toxic
venom
venomous
vertebrate
vicious
viper
vipera
viperidae
viperinae
wild
wildanimal
wildlife
zigzag
zoology