Mr. Brunner, whose real name Chiron, is a centuries-old centaur in charge of activities at Camp Half-Blood. He is initially introduced to Percy, and therefore the reader, as a middle-aged man in an electric wheelchair with “thousand-year-old eyes” who teaches Latin at Yancy Academy. Percy explains that “Mr. Brunner” was not just understanding of Percy’s learning disabilities, but he “accept[ed] only the best from [him].” Mr. Brunner’s unwavering faith in Percy made him Percy’s favorite teacher, even though Percy sometimes felt that he pushed him too hard. However, Percy soon learns that his Latin teacher is actually Chiron, the great trainer of heroes like Hercules, Jason, and Achilles. Long ago, the gods granted his wish to guide heroes for “as long as humanity needed [him].” Now, he trains demigods at Camp Half-Blood to prepare them for their difficult lives. Chiron loves his job, but he has also known great loss as most heroes and demigods eventually die tragic and often violent deaths. However, he has remained at his post for thousands of years to help protect demigods to the best of his ability.
The Lighting Thief, and the rest of the books in the series, is a classic coming-of-age adventure story. Chiron represents the genre’s archetypical wise, old teacher who guides their pupils while still allowing them to make their own decisions; as such, he provides Percy, Annabeth, and Grover with a modicum of guidance on their quest while trusting them to handle most of it on their own. Chiron will continue to play a similar role throughout the rest of the books in the series, offering support and the occasional advice while the young heroes chart their destinies.