Wispy

The "Wispies", as labelled by the Twelfth Doctor, were a gaseous humanoid species native to Venus. They were made of carbon dioxide, nitrogen, and sulphuric acid. In the 2090s, the Genetrix probe sent out atmospheric sifters into Venus's atmosphere. As the Wispies were made of the atmosphere, they were sucked up by the sifters. One Wispy attacked the Genetrix. The Doctor and Clara materialised onboard, and the Doctor purged the sifters. The Wispies lifted the Genetrix back up to the Lovell Platform. (PROSE: Sunset Over Venus)