Pricklepines are only pictured in The Incomplete Book of Dragons.
It is possible that the name Pricklepine refers to a group of similar dragons, like a Genus. The Incomplete Book of Dragons mentions very briefly one specific type of Pricklepine, the Greater Pricklepine. One might assume this species of Pricklepine is larger than other Pricklepine species.
Not a great deal of information is given, other than Pricklepines have long spines all over their bodies and that it would be painful to sit on this dragon. The single image of them shows them to be a dark green color.
Pricklepines are mentioned in this reference book, though not much information is given