The Adipose are creatures that are made of human fat.
The Adipose originally came from the planet Adipose 3. After the Adiposian First Family lost the nursery planet, they hired wet nurses in order to find new places to breed their offspring. On Earth, the wet-nurse Matron Cofelia set up Adipose Industries and disguised the Adipose seeds in the form of weight-loss pills, using humans as surrogates. The pill was gaining over a million customers quickly. When the Tenth Doctor and Donna Noble discovered the alien secret behind the supposed diet pills, Matron Cofelia ordered the immediate birthing of all Adipose. The Adipose nursery ship collected the babies then ordered the death of "Miss Foster", as Cofelia was known, to remove any evidence, as breeding on a Level 5 planet was an illegal act under the Shadow Proclamation. After being taken from Earth, the Shadow Proclamation took the baby Adipose into care.
In 2010, an Adipose was at a bar where the Tenth Doctor came to visit Jack Harkness one last time before his regeneration.