snake in the grass

plural snakes in the grass

1. derogatoryinformalA hidden enemy.

   Is he not here to throw us out—a thief, a spy, a snake in the grass?

   1914, William MacLeod Raine, “‘An Optimistic Guy’”, in A Daughter of the Dons: A Story of New Mexico To-day, New York, N.Y.: G. W. Dillingham Company, →OCLC, page 71

   4 more examples

   The trouble is, I trusted him too much from the start. He has proved to be a snake in the grass.

   1906, Horatio Alger, Jr., “The Iron Works Affair”, in Randy of the River: Or The Adventures of a Young Deckhand (Rise in Life Series), New York, N.Y.: Grosset & Dunlap, →OCLC, page 57

   He's a snake in the grass, I tell you guys / He may look dumb but that's just a disguise / He's a mastermind in the ways of espionage.

   1973 June, Charlie Daniels, “Uneasy Rider”, performed by Charlie Daniels, New York, N.Y.: Kama Sutra Records, →OCLC

   We were playing in Dallas, when that snake in the grass—Eight Ball, everyone called him—came up on my blind side …

   1978, John Irving, “The World According to Marcus Aurelius”, in The World According to Garp […] (A Henry Robbins Book), New York, N.Y.: E[dward] P[ayson] Dutton, →ISBN, pages 271–272

   Following her presidential defeat, [Ségolène] Royal stunned many observers by publicly dumping Socialist Party leader François Hollande – her companion and the father of her four children – and announcing she'd seek his post during the current election. To some, that made Royal the symbol of the strong, modern woman in politics; to others, it cast her as the classic snake in the grass.

   2008 November 21, Bruce Crumley, “Which Woman will Lead France’s Socialists?”, in Time, New York, N.Y.: Time Warner Publishing, →ISSN, →OCLC, archived from the original on 16 Jan 2012

   Synonyms: backstabber, wolf in sheep's clothing, backstabber, betrayer, cockatrice, double-crosser, quisling, rat