Harley Spiny is the young protagonist of the Japanese anime series Harimogu Harley. He is a male echidna, a spiny, ant-eating mammal, who lives with his parents in a vibrant community known as Animal Village. Harley is characterized by his boundless energy, mischievous nature, and intense curiosity about the world around him. These traits form the core of his personality and drive many of his daily adventures and misadventures. He is described as a small and playful child, yet his curiosity is so powerful that it often leads him into various kinds of trouble. One of his strongest and most defining motivations is his dream to meet a human being for the first time, a quest he pursues frequently, though he always seems to fail at the very last moment.

In the context of the story, Harley acts as the energetic heart of his group of friends, which includes a squirrel named Risuko, a mandrill named Takuya, an elephant named Agezo, and a crocodile named Gaburine. His role is often that of the instigator, whose playful and inquisitive nature pulls his companions into new situations within their village and school. His key relationships are varied. He shares a competitive and quarrelsome dynamic with Takuya, who often teases Harley. Takuya refuses to call him by his given name, instead using the full, formal-sounding name Hariyama Moguo, which is a reliable way to anger the echidna. Beyond his circle of friends, Harley is known to frequently chase and be chased by a mole cricket named Kerasuke. At home, he lives with his father, a carpenter with a relaxed personality and a loud snore, and his mother, who is skilled at cooking but becomes terrifying when she is angered, revealing a firmer, more disciplinarian side.

Throughout the series, which ran for 140 episodes, there is little indication of a significant, permanent shift in Harley's fundamental character. Instead, his development is episodic, typical of a children's slice-of-life series, where he learns small but valuable lessons from his daily escapades. His most notable ability is directly tied to his emotions. When he becomes genuinely angry, his spines stand on end, and he unleashes a powerful charging attack called the Haryarinpa. This technique is portrayed as incredibly strong, something that no one can stop once he has started it. This ability serves as both a comedic outburst and a testament to the raw, uncontrollable power contained within the small, cheerful echidna.