The raptor is a metal head featured only in Jak X: Combat Racing. It is a tall, frail macropod-like beast that relies on its incredible speed to survive, and is otherwise defenseless (similar to the scout from Jak II).
The raptor is the very last type of metal head to appear in the Jak and Daxter series, and considering its victimization for sport, perhaps represents the dwindling status of the species as a whole following the death of both Kor and Errol, the leaders of the species in Jak II and Jak 3, respectively. It is presumed that the raptors, who aside from their speed were defenseless, were captured and then released onto the tracks for entertainment purposes.
Specifically they were released on the Clifftop Battlefield for the sport hunt combat racing event in the Kras City Grand Championship (also the Wasteland Isle in exhibition mode). Racers would then compete to kill as many as possible before time expires.
Raptors are considerably fast but just as weak, therefore hunting them is all about speed. Pick a race car with an efficient turbo system and a high engine statistic, then focus on picking up yellow eco and hunting them down. Tracking missiles will be the most useful at long range, and can quickly lock on to them due to their obvious indication (green dots on the minimap and a gray highlight onscreen). The Vulcan Fury is more effective at short range, and can be used in combination with ramming them at high speeds (which will also easily kill them).