Shard

A Shard was a form of sentient sunlight. Imprisoned by the Eleventh Doctor, a Shard was trapped in the back of a 1950’s ambulance and sent back in time to be trapped in a glacier. Thousands of years later the Shard was released by an expedition in Antarctica and, after seeking revenge on the Doctor, was planning to destroy the universe, one planet at a time. But the Doctor had deliberately chosen the glacier in the vicinity of a decompression tank. He used it to trap the Shard and deprived of oxygen, extinguishing it for ever. (DWAM: Vacuum Packed)