Species (The Doctor, the Widow and the Wardrobe)

An unnamed species made a failed invasion of Earth in 1938.

Technology
This species had long black spacecraft. (DW: Prequel (The Doctor, the Widow and the Wardrobe)) They also used impact suits, which were spacesuits that could survive great amounts of damage. (DW: The Doctor, the Widow and the Wardrobe)

History
In 1938, they attempted to invade Earth, believing themselves unopposed. (DW: The Doctor, the Widow and the Wardrobe) The Eleventh Doctor broke into the ship while it was in orbit and rigged it to explode when he removed his finger from a button. He tried to get Amy Pond to bring the TARDIS to him, but only then remembered he was travelling alone. (DW: Prequel (The Doctor, the Widow and the Wardrobe)) The Doctor was barely able to survive the explosion, stealing an impact suit and falling to Earth. (DW: The Doctor, the Widow and the Wardrobe)