Adder or Viper
I saw this Adder / Viper at the end of February this year, it was basking in the sunshine alongside a rural path. It's only the second one I've seen in the twelve years we've lived near the New Forest.
The Adder - Vipera berus -
is the UK's only poisonous snake. It is protected by law.
This one was slightly less than a foot (30 cm) long. The body at the head about the diameter of my little finger but the rest of its' body was quite rounded, which made me think it was a female.
.....If you have a spare moment, please visit my vfxy.