In the latest new seasonal game mode from Overwatch, Yeti Hunter, play as one of five Mei's to hunt down the Yeti Winston (for science). Build up your ultimate ability, a Junkrat style trap, and find a meat spot to place it next to. Wait for the Yeti to get trapped and the achievement is yours. Good luck!
NOTE: This achievement can only be unlocked during the seasonal Winter Wonderland event! This will run from December 12, 2017, through January 1, 2018.