The DC live-action universe has had its share of highs and lows, but there's one character that Warner Bros. is putting serious stock in: Harley Quinn. Margot Robbie's hilarious villain debuted in David Ayer's Suicide Squad, and she'll reprise her role in that movie's sequel, as well as Birds of Prey (and the Fantabulous Emancipation of One Harley Quinn). Robbie is also a producer on the upcoming blockbuster, and she recently explained why she loves playing the character so much.