Claudius in William Shakespeare's Hamlet, is a "smiling villain," charming and courteous, but nonetheless amoral and unscrupulous. He is Hamlet's uncle, being the brother of Hamlet's father.
At the opening of the play, Claudius has married Gertrude, Hamlet's mother. The ghost of Hamlet's father informs Hamlet that Claudius actually murdered Hamlet's father. Hamlet acknowledges the ghost's point that he has a duty to avenge the murder of his father. The main plot of the play consists of Hamlet trying to ascertain solid evidence of Claudius' misdeeds, deciding to kill him, and figuring out how that murder might be accomplished.
At the end of the play, Claudius puts poison in Hamlet's drink. Gertrude, Hamlet's mother drinks some of it by mistake and dies. Meanwhile, Laertes wounds Hamlet with a poisoned sword, but Hamlet by accident ends up with the poisoned sword and stabs Laertes with it. When Hamlet discovers that the sword has been poisoned, he stabs Claudius with it, saying:
The point!--envenom'd too!
Then, venom, to thy work.
Hamlet then forces Claudius to drink the remainder of the poisoned drink, saying:
Here, thou incestuous, murderous, damned Dane,
Drink off this potion. Is thy union here?
Follow my mother.