Adipose

The Adipose were a race of vaguely humanoid blobs of fat.

Biology
Young Adipose were hand-sized, marshmallow-shaped beings, composed almost entirely of fat. They weighed at least one kilogram, as Roger Davey, who used the Adipose pills, said it was the exact amount of weight he lost each night. They had two eyes and a mouth, two arms with webbed hands and two stumpy legs. Most Adipose were harmless and cute creatures. (TV: Partners in Crime)

Life cycle
The Adipose reproduced on Nursery Worlds. When on Earth, the Adipose's development was started when a pill from Adipose Industries was ingested. The young Adipose would grow, collecting fat from around the body. Every night, the Adipose would then be born and leave the body. They could convert other material into fat; however, this practice was not good for their health. Alternative materials included the bones, organs, muscles and many other human tissues. In emergencies, this was used to dispose of people by turning them completely into Adipose. (TV: Partners in Crime)

Technology
Adipose technology included the pills used on Earth to germinate young Adipose, nursery ships equipped with levitation beams and sonic pens. (TV: Partners in Crime) At one point the Adipose society had its own televised news media. (COMIC: Cold Blooded War!)

History
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 gained 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. (TV: Partners in Crime) After being taken from Earth, the Shadow Proclamation took the baby Adipose into their care. (WC: )

Later the Doctor and Donna discovered Adiposes left on Earth, and Donna hid them in the TARDIS. (COMIC: Untitled (10DY3 11))

In 2010, an Adipose was at a bar where the Tenth Doctor came to visit Jack Harkness one last time before his regeneration. (TV: The End of Time)

Undated events
A pink Adipose was present at Garage 10. (COMIC: The Ministry of Time)

An Adipose was among the trash the Twelfth Doctor threw away. (COMIC: The Bin Dilemma)

Alternate realities
In a parallel world, the March of the Adipose occurred in the United States. Sixty million people were killed and converted into Adipose. (TV: Turn Left)

Behind the scenes

 * is, in reality, fat tissue of the human body, which is what the Adipose are named after. The real adipose is mentioned in the scientific explanation Miss Foster presents.
 * The Mill made stress balls for themselves designed in the image of the Adipose. A version of these later became commercially available.
 * The computer-generated Adipose came in two forms. Adipose in the background of many shots were created with a form of artificial intelligence to prevent the need of having to individually animate each individual Adipose, but the ones in the foreground were hand animated.
 * Russell T Davies' original concept for the Shadow Proclamation scene in The Stolen Earth included an appearance by several very large adult Adipose, as well as many Adipose children (likely those taken from the Adiposian First Family) but his plans to feature a "rogues gallery" of alien races in the scene fell through; ultimately the Judoon were the only returning race featured.
 * Adipose is used as several playable characters and as an enemy in the Doctor Who: Legacy mobile game.