The antagonist is more complex, as there are multiple characters who act against Hamlet's interests:
* Claudius: Hamlet's uncle, who murders his father, King Hamlet, and marries his mother, Gertrude. He is the most obvious antagonist, directly responsible for Hamlet's grief and fueling his desire for revenge.
* Polonius: The Lord Chamberlain and father of Ophelia and Laertes. He is a manipulative and conniving character who often serves as an obstacle to Hamlet's plans.
* King Hamlet's ghost: While not strictly an antagonist, the ghost's demands for revenge force Hamlet into a dangerous and ultimately fatal path.
It's important to note that Hamlet himself can also be seen as an antagonist in his own story. His procrastination, indecision, and tendency to brood often hinder his progress towards justice.
Ultimately, the complex interplay of characters in *Hamlet* makes it challenging to pin down a single antagonist. Claudius is the most direct villain, but Polonius and even Hamlet's own internal struggles contribute significantly to the tragedy of the play.