Final answer:
The literary term that describes a character who possesses both heroic and monstrous qualities is foil. Another term that could also apply is antihero.
Step-by-step explanation:
The literary term that describes a character who possesses both heroic and monstrous qualities, as seen in characters like Dr. Jekyll and Mr. Hyde, is foil.
A foil character is one who contrasts with another character, typically the protagonist, in order to highlight certain traits or themes. In the case of Dr. Jekyll and Mr. Hyde, Mr. Hyde serves as a foil to Dr. Jekyll, emphasizing the duality of human nature and the struggle between good and evil.
Another term that could also apply, although with some nuances, is antihero. An antihero is a protagonist who lacks traditional heroic qualities and may even possess negative traits, but is still the central character of the narrative.
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