Puck, Santana, and Brittany swapped with the "nerdier" characters, creating a hilarious visual dissonance.

For three seasons, Tina was often relegated to the background, a meta-commentary the show finally addressed head-on in "Props." Feeling like a glorified "costumed background singer," Tina threatens to quit.

Chris Colfer and Cory Monteith swapped roles, with the towering Monteith channeling Kurt’s refined mannerisms.