Antagonist

Antagonists, or simply enemies, are the main villains of the Grand Theft Auto games. The antagonist of a GTA game is usually a person that has betrayed or hurt the protagonist on a personal and social level, and spends the game moving against the protagonist in multiple ways.

Description of Most Antagonists
In the GTA games, the main antagonist is introduced at the very beginning of the game, but as a ally or friend. Sometimes, the antagonist is the main reason that a protagonist visits the city/state. In most GTA games with antagonists, they usually fake a friendship or business relationship with the protagonist then suddenly, in one mission, reveal their hate for the main character and begin to open fire on them with a weapon. The main character always hunts down and eliminates the antagonist eventually.

Antagonists usually have a gang behind them for protection. The main character will battle the antagonist group and usually take them over.

Catalina
Antagonist Group: Columbian Cartel

Killed in: The Exchange

Reason: Shot down by a Rocket Launcher by Claude.

Sonny Forelli
Antagonist Group: Forelli Family

Killed in: Keep Your Friends Close

Reason: Shot dead by Tommy Vercetti

Lance Vance
Antagonist Group: Forelli Family

Killed in: Keep Your Friends Close

Reason: Shot dead at the rooftop by Tommy Vercetti

Frank Tenpenny
Antagonist Group: Tenpenny is/was a member of the Community Resources Against Street Hoodlums, otherwise abbreviated as C.R.A.S.H., who is working out of Los Santos, San Andreas.

Killed in: End of the Line

Reason: Crashed in the heart of Ganton and succumbs to his injuries.

Big Smoke
Antagonist Group: Ballas and Los Santos Vagos

Note: Big Smoke is the top lieutenant in the Grove Street Families but he betrayed the gang and he worked with Tenpenny and Pulaski, along with the Ballas.

Killed in: End of the Line

Reason: Killed in a showdown by CJ.

Massimo Torini
Antagonist Group: Sicilian Mafia

Killed in: The Sicilian Gambit

Reason: Shot Down by Toni.

Jerry Martinez
Antagonist Group: Similar to Tenpenny, Martinez is a corrupt Sergeant for the United States Army and is not in any gang. He does however have control over some gangsters in Vice City that try to kill protagonist Vic Vance, but they are not an official gang.

Killed in: Last Stand

Reason: Killed by Vic.

Diego and Armando Mendez
Antagonist Group: Mendez Cartel

Notes: The Mendezes are the powerful drug cartels in Vice City. However, they want all businesses of Vic and knock Vic and Lance out but all their efforts fail to kill the Vance Brothers.

Killed in: Light My Pyre and Last Stand, respectively.

Reason: Killed by Vic.

Dimitri Rascalov
Antagonist Group: Russian Mafia

Notes: Assuming the Player exacts revenge on Rascalov before the game's climax and kills him, the Antagonist group will become the Pegorino Family, headed by Jimmy Pegorino. Also, Rascalov is not the only antagonist of Grand Theft Auto IV. Darko Brevic is an antagonist as well.

Billy Grey
Antagonist Group: Grey was, for part of the game, head of The Lost Brotherhood but was later arrested and the role of president went to the protagonist Johnny Klebitz.

Killed in: Get Lost

Reason: Executed or killed by Johnny.

Wu Lee
Antagonist Group: Lee Family

Killed in: Salt In The Wound

Reason: Killed by Huang.

Rodislav Bulgarin
Antagonist Group: Russian Mafia.

Killed in: Departure Time

Reason: Executed by Luis in a airplane.