made up by way cool older sister when we were kids and is stil in use today ... was an attempt to be smarter then my parents at swearing..
An alien race from the Whovian universe that came to earth in 1965, asking for 12 children in return for the vaccine to an Earth-born disease that was about to mutate, killing thousands. They were named the 456 after the radio waves they first used to communicate with the United Kingdom's government.
The 456 are large, with three heads, large mandibles, and trunk-like in body. Each has a large bulge at the end of it's body, revealed to be a holding area for children. They live in a very toxic environment.
The 456 returned to Earth in 2009, demanding 10% of the world's children, in return for the safety of the entire world. They announced this return through children, as if using them like radios: "We. We are. We are coming."
The 456 later revealed they wanted the children for personal pleasure, stating the children "felt no pain", and that the prepubescent hormones were like a euphoric drug, connected to their bodies through veins.
The 456 were defeated by Torchwood soon after arriving, but not without losses (Ianto Jones and Steven RIP). They were driven away from Earth, the radio waves they had used to communicate being turn against them.
"Children of Earth" is the mass episode title for the five days the 456 were present in 2009.
John Frobisher: "That is correct."
Voice: "Then that is our name."