What is this trap in QGD? I recently watched an Eric Rosen video where he showcased a trap in the QGD. I do not remember what the trap was called. Here are the moves.
[FEN &quot;&quot;]

1. d4 d5 2. c4 e6 3. Nc3 Nf6 4. Bg5 Nbd7 {The trap is this move, because the d5 pawn is not actually free} 5. cxd5 exd5 6. Nxd5 Nxd5! {And White falls for it!} 7. Bxd8 Bb4+! 8. Qd2 {White is forced to give up their queen since that is his only move} Bxd2+ 9. Kxd2 Kxd8 {Black is up a knight, and has a safer king than White, and White’s only compensation is a pawn. Lichess’s Stockfish rates this to be ~-3.}

I don’t remember the name of the trap. If anyone could let me know that would be great. (Bonus points for anyone who can link me the Eric Rosen video!)
This is known as the Elephant Trap.