Monster

Monster was a term for a frightening lifeform.

The Eighth Doctor said to Destrii that he was not scared of monsters, but that monsters were scared of him. (COMIC: Uroboros) He later repeated this claim to Elliot Northover while in his eleventh incarnation. (TV: Cold Blood) The Tenth Doctor said that monsters had nightmares about him. Jeanne-Antoinette Poisson realised that one could not have the Doctor without the monsters, but that the Doctor was worth the monsters. (TV: The Girl in the Fireplace)

Among the life forms which were called monsters were dinosaurs, (TV: The Underwater Menace, Invasion of the Dinosaurs) Silurians, (TV: Doctor Who and the Silurians) Kronos, (TV: The Time Monster) Linx (TV: Invasion of the Dinosaurs) the Exxilon City, (TV: Death to the Daleks) Aggedor, (TV: The Monster of Peladon) the Mutos and the Daleks, (TV: Genesis of the Daleks) Erato, (TV: The Creature from the Pit) Reapers, (TV:  Father's Day) the Krafayis, (TV: Vincent and the Doctor) the Minotaur, (TV: The God Complex) the Crooked Man, (TV: Hide) the Foretold, (TV: Mummy on the Orient Express) the Boneless, (TV: Flatline) the Sandmen, (TV: Sleep No More) a creature living in the River Thames (TV: Thin Ice) and the Eaters of Light. (TV: The Eaters of Light)

Vorg called his miniscope "the monster show" and "a carnival of monsters". (TV: Carnival of Monsters)

The term was also given to immoral persons or groups. Sharaz Jek called Morgus an inhuman monster. (TV: The Caves of Androzani) Ianto Jones called Jack Harkness "the biggest monster of all." (TV: Cyberwoman) Carla Langer called her ex-husband Paul a monster. (TV: The Mark of the Berserker) The Tenth Doctor called the human race monsters after Harriet Jones had the Sycorax destroyed. (TV: The Christmas Invasion) called the human race the "greatest monsters of them all." (TV: Last of the Time Lords) Clara Oswald called the Time Lords monsters. (TV: Hell Bent)

George was terrified of monsters and pleaded for someone to save him from them. (TV: Night Terrors) Ada Gillyflower called the Eleventh Doctor her "dear monster". (TV: The Crimson Horror) Erik set up recordings of monsters around his cottage so that his daughter Hanne wouldn't leave it. (TV: It Takes You Away)