The Eternal Dalek was one of the five Daleks from the Paragrim.
The Eternal Dalek was the second Dalek from the Paragrim machine. The Eternal is yellow. After all the old Daleks were exterminated by the Supreme White Dalek the Dalek put the lights up in London so that the German's could bomb London. Winston Churchill sent spitfires up to destroy the dish and he succeed. The Daleks activated Professor Bracewell as he was a bomb.
The Doctor had to choose between destroying the Daleks or destroying the Earth. He chose the Earth and the Daleks managed to escape leaving the Doctor very angry until the next time.
The Eternal Dalek returned at the Pandorica as part of the Pandorica Alliance along with one of the Drone Daleks and a Supreme Dalek. He put the Doctor inside the Pandorica as he cause the cracks in time. The other members of the Alliance were Cybermen, Judoon, Sontarans, Silurians, Autons and many more.
The Eternal Dalek could have been one of the Stone Daleks at the British Museum who fought against River Song, The Doctor, Rory and Amy
The Eternal Dalek has appeared in:
Series 5: Victory of the Daleks, The Pandorica Opens and The Big Bang