Brakari

Brakari were a type of spacedwelling animals.

Biology
Brakari were globular, jellyfish-like creatures. They were normally bright white with blue specks, but became grey when sick. They could levitate, but when hungry, slithered on the ground. Though they weren't sentient, they took care of their offspring.

The Brakari could travel through the vacuum of space. In order to survive the trip, they drained energy from objects and stored it. A full-grown adult could drain all the energy from a human in seconds. (WC: Snowfall)

History
At some point in the 21st century, a sick Brakari gave birth to an even sicker offspring. They came to Earth and tried to find a source of energy, attempting to drain it from a theatre. When the Eleventh Doctor, Louie Rollins, Millie Peterson, their Aunt Rachael and Big Jack went to the theatre, they also tried to feed on them, but were driven off by the Doctor's sonic screwdriver. When the Doctor learned the truth of the matter, he used equipment from his TARDIS to restore the Brakari to full health. (WC: Snowfall)