Time Weaver

Time Weavers were thoughts to be myths by the Twelfth Doctor. They had extremely long heads, and varied from having golden faces, or darker greyish-blue faces. Their hands were boney, and they had the ability to alter the fabric of reality.

Ethel, one such Time Weaver, spent her eternal life trying to destroy the fabric of reality with her sister and was at odds with her other sister Gretel who would always fix what she did.

When the Twelfth Doctor accidentally landed her TARDIS on Ethel and Gretel's sister, it prompted Ethel to send time flies at both him, Clara Oswald and to all of his previous incarnations. Gretel assisted him and was ultimately able to defeat Ethel. (COMIC: A Stitch in Time)