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The term "worm" was an epithet or insult.
Saphadin called El Akir a "vile worm." (TV: The Crusade [+]David Whitaker, Doctor Who season 2 (BBC1, 1965).) Styre called the Fourth Doctor "worm." (TV: The Sontaran Experiment [+]Bob Baker and Dave Martin, Doctor Who season 12 (BBC1, 1975).) Morbius called the Time Lords "pallid, devious worms." (TV: The Brain of Morbius [+]Robin Bland, Doctor Who season 13 (BBC1, 1976).) Romana called the co-pilot a "despicable worm." (TV: The Horns of Nimon [+]Anthony Read, Doctor Who season 17 (BBC1, 1979-1980).) The Seventh Doctor called Ishtar "a pitiful little worm." (PROSE: Timewyrm: Genesys [+]John Peel, Virgin New Adventures (Virgin Books, 1991).)