Grockle is the dragon formed from a clay bronze egg made from Liz's hand and was kindled by Zanna. At Anders Bergstrom's home, Zanna names the dragon Grockle after the rasping sound he made while trying to find his fire. Grockle, unable to find any fire, turns to stone instantly.
In Fire Star, Golly brings Grockle back to life. The dragon is captured at Farlowe Island while trying to find his father Gawain's fire tear. Later he escapes to the far north. At the end of the novel, he escapes into the dark matter plane.
During Dark Fire Grockle returns under David's command (being illuminated to him). In the book he is older and larger but still not the size of a fully grown dragon as he is small in comparsion to Gawaine. He is present at the battle of Scuffenbury, his fate is unknown.