fat "alien" worm/bug that scares people

This bug was the most frightening thing on the trip. All of us were hiking and then Rey saw this thing. We all thought it was a cocoon for a butterfly that fell on the ground. Rey was not exactly sure what it was, so he picked it up and looked at it. We were crowded around him and also thinking of what this bug could be. It had not moved at all so we thought it was dead. As Rey called everyone else to come and look, it started to squirm like a worm and literally jumped out of Rey's hand. Everyone screamed and ran to a safe distance from the thing. At that point my heart had almost stopped. None of us thought that this thing could move because we thought it was dead!