Jack moved out of the way of the snake and stepped back and up onto a stone. Seconds later, of course, he registered the high pitched noise that had come from the Doctor, and though he really ought to have been looking around himself to make sure there was nothing small (or large) and crawly about to attack him, he instead stared at the Doctor and started laughing.

His laugh was more a giggle than anything and a release of tension as much as anything else. He doubled up on himself a little and smacked a hand against his leg in amusement (which in hindsight he ought not have done considering how his legs hurt).

"Listen to you!" he continued to laugh, pointing a finger at the Doctor. "Mind out the way of the Oncoming Storm over here."