Spyro 2: Ripto's Rage!
Gronk resided near the spot where Spyro began his journey through the land, and he made a bet with his cousin Glug that the dragon wouldn't make it through without getting singed, even though he admitted to having heard Spyro was pretty tough. He ended up losing that bet.
Spyro: Shadow Legacy
He appeared to be leader of the tribe of cavemen and make the greater decisions in the Badlands. When Ooga had secretly hidden their treasured booga-booga mask and blamed Lumpy for doing it, simply because he didn't like him, Gronk took Lumpy to the Cliff of Danger as punishment, however when Spyro found the mask, Ooga became uneasy which alerted the cavemen that Ooga was the thief and Gronk quickly told him to go there, and released Lumpy.