High Quality Content by WIKIPEDIA articles! A toxic leader (or the `board room Hitler`/the `little Hitler/`manager from hell` (or) `boss from hell`) refers to a person who has responsibility over a group of people or an organization, and who abuses the leader-follower relationship by leaving the group or organization in a worse-off condition than when s/he first found them. The phrase was coined by Marcia Whicker in 1996 and is linked with a number of dysfunctional leadership styles.