1. Grotesque Humor: The story incorporates grotesque and macabre humor, such as the king's cruel jest of dressing Hop-Frog and Trippetta as monkeys and the subsequent burning of Trippetta. This humor adds an unsettling and twisted quality to the narrative.
2. Physical Deformity: Hop-Frog is depicted as a deformed dwarf, which was commonly associated with the grotesque in Gothic literature. His physical deformity enhances the sense of otherness and isolation that he experiences.
3. Revenge: The theme of revenge is central to the story. Hop-Frog's meticulous planning and execution of his revenge against the king and seven ministers create an atmosphere of suspense and retribution.
4. Supernatural Elements: While not explicitly supernatural, the story contains elements that border on the uncanny. For instance, the way Hop-Frog transforms the throne room into a furnace-like environment and his ability to control the flames suggest supernatural powers.
5. Atmosphere of Dread: Throughout the story, there is a pervasive sense of foreboding and dread. This atmosphere is created by the constant threat of violence, the claustrophobic setting of the throne room, and the underlying psychological tension between Hop-Frog and his oppressors.
6. Morality and Sin: "Hop-Frog" explores the themes of morality and sin. The king and his ministers are depicted as morally corrupt and deserving of punishment, while Hop-Frog's actions raise questions about the nature of justice and retribution.
7. Psychological Horror: The story delves into the psychological aspects of fear and madness. Hop-Frog's calculated and methodical approach to revenge suggests a deep-seated psychological turmoil, while the king and his ministers' descent into panic adds to the story's psychological horror.
8. Irony: The story employs dark irony, as the king's cruel jest ultimately becomes his undoing. This ironic twist adds to the unsettling nature of the narrative.