Lesli Stone

Lesli Stone is a minor antagonist on Pretty Little Liars.

She was a friend of Mona Vanderwaal's, who came to Rosewood after Mona's supposed death. She seemed sweet, however, unbeknownst to the Liars, Lesli is a patient from Radley.

At Alison's trial, Lesli is called in a surprise witness and trashes the Liars severely.

She returns in Season Six, where the Liars suspect that she is "A".