The hand is at showdown, and the board is paired—say K-K-9-5-4. The victim is reluctant to roll his hand, so the angle shooter—who holds a hand like A5 or 54—very loudly says, "Two pair!" If the victim is fairly new to poker, he may muck a hand like A9 or 88 without showing, focused on the idea he has one pair using his hole cards, not taking into account that the board also has a pair, giving him a decent two pair hand as well.
I saw this angle shot used three times in the past two cash game sessions I've played. It worked once, and nearly worked a second time. In the second case, the player rolled up her hand to show she had caught an Ace to pair her AQ; she thought she had gotten unlucky, and inadvertantly won the pot. In the first case, the angle shooter (a stereotypical young poker d-bag, complete with sunglasses, scruffy beard, and Ed Hardy sweatshirt) rolled his "winning hand" (pocket fours) after his victim mucked, and couldn't stop grinning like the Cheshire Cat when his victim caught on and tried to complain about his mucked hand. The victim cashed out less than an orbit later, still agitated about the hand. Our studly angle shooter won himself a nice $30 pot, and drove a bad player and his remaining $200 (and who knows how much more) from our game, and possibly from live play altogether. I hope it was worth it.