This word appears in the book and movie "A Clockwork Orange", though somewhat modified. The slang of Alex and his droogs is heavily influenced by the Russian language. "Horrorshow" becomes an adjective meaning "great". In the scene is telling his M that he won't be going to school that day, he complains of a "terrible ache in his gulliver", which comes from the Russian word gulova, which means "head".
See also a Nadsat glossary.