A 10-year-old girl spent nearly a week in hospital in agony after being bitten by a snake in Bournemouth, England.
Mollie's leg swelled up to three times its size and turned black after she was bitten on the toe by the 45cm adder while out on a walk.
Doctors said it was one of the worst bites they had ever seen.
Snake bites are really rare in the UK. The adder is the only wild snake that can harm and usually will slither away rather than attack a human.
Mollie accidentally stepped on the snake as she walked through a nature reserve in Bournemouth with her mum last week.
She's now recovering at home in Poole, Dorset, but still needs to use crutches to get around.
Her mum, Karen, said: "I just didn't realise snakes in Britain could do so much damage."
The adder is Britain's only venomous snake and about 100 people a year are bitten.
An RSPCA spokesman said that to even see a snake was rare in the UK.
"If you see a snake in the UK, then you are quite fortunate, but it's best not to try to handle them."