Hair: short, bristly, extends down onto his forehead.
Eyes: small, dull, deep-set.
Voice: low and raspy (CS12).
Distinguishing features: thickset and extremely mean, "almost as stupid as he [is] mean". Polyjuice Potion to turn someone into Goyle is the khaki color of a booger (CS12).
Age: born 1980.
Ancestry: Goyle's ancestry is never mentioned in the books, however, in 2001 Rowling flashed a notebook during a BBC interview that showed her notes on the students in Harry Potter's year and Gregory is noted as being a Pureblood. This information cannot be considered canon, however, because the notes conflict in too many places with the stories as they were actually published.
Gregory Goyle is one of Draco Malfoy’s thuggish cronies. Goyle has short, bristly hair that extends down onto his forehead. His eyes are small, dull, and deep set, and he speaks with a low, raspy voice. He’s a mean bully who enjoys whatever chance he gets to boss people around, whether as a member of Umbridge's Inquisitorial Squad in his fifth year or using the Cruciatus Curse on other students in his seventh. Polyjuice Potion to turn someone into Goyle is the khaki color of a booger (CS12). Goyle’s interests include chuckling trollishly, smirking, laughing syncophantically, cracking his knuckles, flexing his muscles, sniggering stupidly, and rubbing his knuckles in a menacing way. He doesn’t like writing. Why is that not surprising? (OP10). Goyle's father is a Death Eater (OP).
Goyle = from "gargoyle" stone demons carved into the exterior of Gothic buildings as rain spouts.
In the films, Goyle is played by Joshua Herdman.