The Mkali were advanced race that came from beyond the solar system. They were similar to humans, but they had pointier ears and purple skin around their eyes. They used purple mushroom-shaped spacecraft.
In the 21st century, two Mkali enrolled their son into a school in England under the name Ralph. One day, Ralph became angry and used Mkali technology to turn his classmates into violent mindless beings. The Twelfth Doctor and Jata discovered what was going on and contacted Ralph's mother, who came to the school and took Ralph away. (COMIC: Fear Buds)