Molai

The Molai were a race of knee-high piggish creatures that shared a group mind. They were one of the lesser races affected by what they called a hidden war spreading across the galaxy, erasing their entire history.

A group of Molai that were offworld at the time were unaffected, and put their planet to sleep before proceeding to travel the galaxy and steal memories from other planets, though they called it "borrowing." An individual would see the "ghost" of an ancestor before the ghost disappeared, and they would have no memory of the ancestor altogether. They planned to use these to create a new race memory for the Molai.

In Geneva, 1981, the Molai were confronted by the Fourth Doctor, Leela, and Alistair Gordon Lethbridge-Stewart, who had each had a memory stolen. The Doctor explained that they could just copy memories, but the Molai spokesperson said it was beyond them; the Doctor offered to teach them techniques that his people used to copy and transfer memories, and they agreed to return the memories stolen that they would copy. (AUDIO: The Revisionists)