Alex Drake is a fictional character from the television series Pretty Little Liars. She is introduced in the seventh season as the twin sister of Alison DiLaurentis, a central character in the show. Alex is known for her complex personality and her role as the main antagonist, revealing her motivations and connections to the other characters. In the series, Alex adopts the alias A.D. and orchestrates a series of manipulative schemes against the main characters, known as the Liars. Her character explores themes of identity, family dynamics, and the impact of trauma, contributing to the show's suspenseful narrative.