Grima Wormtongue is the tertiary antagonist of The Lord Of The Rings: The Two Towers.
He is portrayed by Brad Dourif who also voiced Chucky.
The Lord Of The Rings: The Two Towers
Wormtongue was once a man of Rohan, but betrayed them for Saruman, and they were manipulating Théoden, the king of Rohan. It is strongly implied that after Théoden's son Théodred was wounded by orcs, Wormtongue poisoned him in his sleep. Saruman promised to give him Eowyn in return for his service. When Eomer stood against him, Wormtongue banished him. Eventually Saruman's control over Théoden was broken by Gandalf. Théoden tried to kill Wormtongue, but Aragorn stopped him, telling him enough blood has been spilt on Wormtongue's account. Wormtongue went back to Saruman in Isengard.
He was trapped in the tower of Orthanc along with Saruman when the Ents flooded Isengard. His final fate is only shown in the extended version, however; During Gandalf and Théoden's talk with Saruman, Wormtongue appeared and Théoden offered him the chance to go back to his side. Wormtongue wished to accept, in order to escape Saruman's beatings, but Saruman slapped him. As Saruman was about to reveal where Sauron was about to attack next, Wormtongue grabbed a knife and stabbed Saruman in the back, twice. In an attempt to stop him, Legolas shot Wormtongue with an arrow, killing him, but the damage was done; Saruman fell from the balcony of Orthanc and was impaled on the spike of one of his war machines.