The Chimerons (pronounced as "Shimer-ons") are a sapient humanoid species from the planet Chumeria, which operate in a hive society, vaguely analogous to Earth's bees.
Born from large green eggs, their infants initially resemble dark green grub-like creatures. While the drones retain this wrinkled and green appearance into adulthood, the adult queens are indistinguishable from Humans.
The larvae grow in an unbelievably fast rate, developing into relatively independent humanoid-looking children within a few hours. Those destined to become queens are fed with a substance known as Chimeron jelly, rich in nutrients and hormones which further accelerate their growth, enabling them to reach adulthood within a single day. The beginning of adult life is marked by the time the young Chimeron queen is able to control her "singing": the ability to produce high frequency calls, which can be used for communication as well as defense. The jelly is also shown to be able to transform adult Humans into Chimeron hybrids.
Their home world of Chumeria used to be known as the "Garden Planet of the Universe", but was devastated by a war with the Bannermen, which intended to drive the Chimerons to complete extinction. The last drones died to enable their queen Delta to escape along with her egg. She tried to trick her pursuers, escaping in a time-traveling tour organized by Navarinos, which ended up landing on Earth in 1959. Unfortunately, a group of Bannermen tracked her and followed. On Earth, the egg hatched and a new princess was born, fed with royal jelly to develop into adulthood quickly. The Doctor, Melanie Bush, Rachel Defwydd, Billy and Goronwy all helped protect Delta and her daughter. Eventually, the Princess reached maturity and was able to use her amplified singing to put the Bannermen out of combat, allowing them to be arrested. Meanwhile, Billy, who had fallen in love with Delta, decides to consume some of the jelly and turn himself into a member of the Chimeron race as well. He leaves Earth with Delta and the Princess, preventing the extinction of the species.
- There are clues that indicate that the distinct white uniform worn by the Chimerons may be actually part of their bodies. This is speculated from the facts that the Chimeron princess goes from childhood to adolescence within hours and is always seen wearing clothes that fit her. Also, Billy, once transformed into a Chimeron himself, is seen wearing the same attire, which likewise fits him perfectly. If this is true, however, the clothes must be made of dead tissue which is easily and harmlessly removable, seen that Delta changes clothes through the serial, as she is given new ones by Mel.
- It isn't clear in the episode whether all female Chimerons become queens. It is reasonable to suppose that female drones/workers likely exist, but whether their appearance more closely resembles the males or the queens is completely unknown.
- Doctor Who, season 24 (Seventh Doctor) - Delta and the Bannermen (1987)