Ghosts

Supernatural or not, these spooky spectres often make for a Doctor Who story replete with Hanna-Barbera-style shenanigans
Podcast
N121 Before the Flood
Doc breaks Beethoven’s fourth wall to explain how a tall chap who turns people’s souls into ham radios can plot to invade the Earth from beyond the grave
Podcast
N120 Under the Lake
Doc leaves Clara hanging in a haunted underwater research facility or military base or oil rig