A Tesco delivery driver had just dropped off Harriet Stapley’s shopping when the 30-year-old found the little crustacean sitting on top of some yoghurts she had bought for her son Jack.
The mother-of-three thought it was dead at first, but after her little boy took it outside, they soon found otherwise.
Harriet said: "I thought it was dead. I told my three year-old son Jack, who took him outside - and then he started to move.
"Then I thought what do I do with a live crab. I didn’t want him to die."
Tesco customer services advised her to ring the RSPCA, but she couldn’t get hold of anyone there so she rang Tesco again.
She said: "Tesco said they would come and pick him up and release him into a lake. "I just thought ’I can do that myself’."
So she filled a bucket with water and released the little critter into a nearby lake.
A spokesperson for Tesco said online deliveries in the area come from a warehouse in Aylesford which, as far as they know, doesn’t keep live animals or fish, so they are really confused.
The spokesperson said: "It’s difficult to explain how the crab has made it so far away from its natural habitat but we’ve promised Ms Stapley we’ll investigate."