elephant trap

noun2

1. •
   (figurative) A trap which can easily be avoided by a competent person, and thus proves the incompetence of anybody trapped by it.

   • To show he doesn’t do his fair share of work, I’ve set him an elephant trap. If he falls in he’ll look like a clown.
2. •
   (figurative) Often in the form Elephant Trap: a faulty attempt by White to win a pawn in a popular variation of the Queen's Gambit Declined, which is generally only effective against inexperienced players.