Antagonist

Antagonist An-tag-o-nist   a person who actively opposes or is hostile to someone or something; an adversary. Basically bad dude.

Example
There are many antagonists throughout literature, movies, television shows, and games. There are even some in the Lord of the Flies.

Examples in Literature

 * Professor Moriarty ( Sherlock Holmes)
 * Sauron (LOTR)

Examples in Film

 * Darth Vader (Star Wars)
 * They guy who shot Bambi's mom (Bambi)

Quotes
In the Lord of the Flies Jack is the main antagonist."Kill the beast! Cut its throat! Bash him in!" this the famous quote he said while killing Simon.