Adipose
Adipose were first seen in Partners in Crime (Series 4 : Episode 1), originally from the planet Adipose 3, which was lost (eventually revealed to be in the Medusa Cascade as part of the Daleks master plan at the end of Series 4). Following the loss of the nursery planet Adipose 3, the Adipose families hired wet nurses to find new planets to breed the Adipose offspring. On Earth, wet nurse Matron Cofelia set up the Adipose Industries, disguising the Adipose seeds for reproduction as weight-loss pills, using human beings as surrogates. The pill was well received as a weight-loss drug; however when the Tenth Doctor and companion Donna Noble discovered the secret behind them, Matron Cofelia ordered the immediate birthing of all Adipose. Under the Shadow Proclamation, breeding on a Level 5 Planet such as Earth was illegal, and after the Adipose Nursery Ship collected the baby Adipose, they ordered the death of Matron Cofelia to destroy any evidence of the illegal activity. After being taken from Earth, the Shadow Proclamation took the baby Adipose into care.
In an alternate reality, the March of the Adipose happened in the United States, killing 60 million people and converting them into Adipose. The Adipose technology included the supposed weight-loss pills used on Earth to germinate the young Adipose, as well as sonic pens and Nursery Ships with levitation beam devices. When the pill was ingested, the young Adipose would grow inside its surrogate human, collecting fat from around the body. Every night, the Adipose would be born and leave the body. Though they could convert other material into fat, the practice isn’t good for their health. Alternative materials included muscles, bones, organs and many other human tissues. In emergencies, people could be disposed of in this way by converting them completely into Adipose. Young Adipose were hand-sized and marshmallow-shaped beings, composed almost entirely of fat. They had webbed hands, two stumpy legs, two arms, two eyes and mouths as part of their anatomy. The Adipose were also breifly seen when the Tenth Doctor met Captain Jack Harkness near the end of his regeneration, in the Zaggit Zagoo bar.