protagonist and antagonist examples...

A protagonist is the centre character in a story whose actions depict both good and bad qualities in that, they may be trying to get revenge on a person that has wronged them in the past but they will probably have to kill that kill this person in order to exact it.

An antagonist is primarily the character who is against the protagonist but does not necessarily have to be human, i.e. could be a force of nature, an animal or simply just turned by the unfortunate circumstances he/she has become involved with.

Reservoir dogs (1992, Quentin Tarantino) is a film about seven criminals in the aftermath of a bank robbery gone wrong. The characters are all strangers to each other and only refer to each other by synonym names, like Mr Blonde. They each have central skills to pull off the heist that has been set up by a crime lord which they are all familiar with.
Mr White shows signs of being a protagonist from the beginning, caring for a member of his team that has been shot, despite even knowing his name. He constantly defends himself and others whom he believes to be innocent in being a snitch and prefers the less violent approach to solving what went wrong rather than go in guns blazing. Although technically they are all antagonists, seeing as they have just committed a major crime, he seems the more human of the group and shows the most regret for it.

Jaws (1975, Steven Spielberg) is a classic example of the antagonist character not being a human. The film revolves around a new police chief in Amity, an island resort town somewhere in New England. He has a wife named Ellen and two sons named Michael and Sean which gives a sense of normality and draws sympathy towards our main protagonist. On a summer morning, police chief Brody is called to the beach, where the mangled body of summer vacationer Chrissie Watkins has washed ashore. This is where the plot thickens. It is discovered that a great white shark is roaming the waters of this ‘summer paradise’ and killing the locals who swim there.
We see in most scenes the victims from the shark’s point of view, sneaking up to them from beneath the murky water and accompanied by the unforgettable bone chilling music that scared many off going the beach ever again. The element of surprise is key in this film as the actual shark is never seen until close to the end of the movie, a moment that had people jumping from their seats in absolute horror.

Natural born killers (1994, Oliver Stone) the film revolves around the misadventures of Mickey and Mallory Knox - outcasts, lovers, and serial killers. They travel across Route 666 conducting psychedelic mass-slaughters but not for money, not for revenge…just for kicks. Glorified by the media, the pair become legendary folk heroes; their story told by the single person they leave alive at the scene of each of their slaughters.
It’s difficult to see these two characters as actually being human. The only true emotion they seem to have is the unconditional love that they have for each other. Mallory has very child like qualities but in no way needs to be looked after and Mickey is very head strong and easily irritated by stupid questions. The movie is fast paced and one big adrenalin rush that keeps up with their violent personalities. Mickey and Mallory Knox are antagonists for their pure hatred and malicious behaviour but at the same time it’s just an extreme example of media satire and modern day violence.