Image Credit: FilmMagic Cooper Koch quickly rose to prominence thanks to his breakout role in Netflix's anthology series Monsters: The Lyle an Erik Menendez Story. The Los Angeles-born actor portrayed Erik Menéndez, one of the infamous brothers convicted of killing their parents in 1989, and his chilling yet layered performance drew widespread attention. Cooper revealed that he immersed himself in Erik's personal history to fully embody the role - a commitment that clearly paid off, as it earned him his first Primetime Emmy nomination in 2025.