Gríma Wormtongue is a fictional character from J.R.R. Tolkien's The Lord of the Rings, serving as a manipulative advisor to King Théoden of Rohan and a secret agent for the wizard Saruman. Known for his "wormtongue" nickname due to his deceitful words, he poisons Théoden's mind and body, weakening Rohan for Saruman's benefit. After Saruman's defeat, Gríma follows him to the Shire, where he eventually kills Saruman and is then killed himself.