Antagonist

dictionary definition:
An antagonist (from Greek ἀνταγωνιστής - antagonistes, "opponent, competitor, rival") is a character, group of characters, or an institution, who represents the opposition against which the protagonist(s) must contend.

my definition:
The rival or opponent of the protagonist and also represents opposition against the protagonist.

example:
one example is like Bruno and Gretal in the story "The boy in the striped pajamas".

how it relates to __The Boy in the Striped Pajamas:__
it relates to The Boy in the Striped pajamas because Bruno and Gretal have a rivalry to show which one is right and which one is wrong

illustration:
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