Species (The Door to a Winter Long Ago)

Aliens from another dimension arrived in London, 1964 due to a time corridor the Eleventh Doctor accidentally created when accidentally jettisoning a room in the TARDIS. (COMIC: The Door to a Winter Long Ago)

Biology
These aliens lived in another dimension, and could travel through time corridors. They were black creatures with no face other than a mouth. They could vary from having two or three arms. They could also fly with ease. (COMIC: The Door to a Winter Long Ago)