Eliza (Knock Knock)

Eliza was the mother of the Landlord.

Near death
In 1947, she caught a deadly illness and the doctors had given up on her. However, her son brought her what he thought were insects from the garden to try to cheer her up. They were in fact space termites. Once she was left alone and left her music box open, the sound awakened them and they sensed that she was sick. They thus began transmuting her body into wood in order to preserve her before she died.

PRESERVATION
When her son discovered the space termites' abilities, he tamed them and for the next seventy years, would lure young people looking for accomodations to their house. The termites would then proceed to absorb the victims and transfer their life energies into Eliza to prolong her life. As he got older but Eliza remained preserved, he also told her he was her father in order to prevent her from objecting to such an obscene decision.

In 2017, Bill Potts and a few other classmates looking for student accommodation were invited by the Landlord into their house. Once the Twelfth Doctor, who was helping Bill move in, deduced something was amiss, the house proceeded to absorb Pavel, Paul and all the other students except for Bill and the Doctor.

Bill found Eliza first and witnessed a horrific display of the preservation process when the termites absorbed her friend. Eliza expressed regret over it but claimed she had no choice. The Landlord then arrived with the Doctor who offered his help.

Death
After he pieced together what was happening, Eliza remembered the Landlord was in fact her now aged son and was utterly horrified by all the people he had killed just so she could live. He then proceeded to summon the termites to kill the Doctor and Bill. Eliza managed to use her connection to them and made them disperse. She then hugged her son and caused the termites to devour them in order to put an end to the madness.

As her last act, she also had the space termites restore Bill's friends as she had never fed on their life energies, thus saving them. The termites then caused the entire house to disintegrate. (TV: Knock knock)

personality
Eliza was a kind and compassionate young woman. Though the preservation made her slightly naive and believe that the Landlord was her father rather than her son, she eventually remembered and was horrified and disgusted by the lengths he had gone to just to keep her alive.

She had also grown immensely lonely during the seventy years of her preserved state. This was a deciding factor in her decision to kill herself and her son as she reasoned that life was not worth living if she was isolated and locked away from the rest of the world.