Two visitors at Rotterdam Zoo have captured the moment a polar bear almost shatters a submerged pane of glass in his enclosure with a rock.
The two men, filming the side of the bear's enclosure, capture the animal swimming around before they are caught by surprise as a rock thunders against the glass.
Fortunately for the men, the pane was strong enough not to shatter. The arctic beast has been relocated to a different pen while the glass is repaired.
The young polar bear, bizarrely named Vicks after the company 'adopted' the cub when he was born, is described by the zoo as "playful" and enjoys playing with stones, making it likely he was simply playing around with rocks rather than attempting a daring escape from his enclosure.
The video is reported to have been recorded on Wednesday.
Vicks was born at the Rotterdam Zoo in December 2010 to his mother Olinka. He became something of a national celebrity when 420,000 people watched the early months of his life on a webcam feed in his darkened maternity den.
You can watch all of the zoo's video of Vicks' life, from his days as a tiny cub, to now, below.