Greater Pricklepines are mentioned inThe Incomplete Book of Dragons.
There is no information or description, but obviously this dragon is prickly — has a lot of spikes — as the eggs are shown to even be prickled, as well as the species name. The egg is green-grey in color, with spikes coming out of the entire surface.
It is possible that this is a type or species of Pricklepines, specifically a larger sized one (hence "Greater" in the name).
A Greater Pricklepine egg appears in a section of this reference book discussing dragon eggs.