This is a real North American porcupine skull! These skulls are available worldwide and are roughly 10cm long.
The North American (Erethizon dorsatum) porcupine is a rodent native to the coniferous forests of Alaska, Canada, much of northwestern United States and as far south as northern Mexico. It is the second largest rodent in North America after the beaver, reaching lengths between 60-90 cm (2.0 to 3.0 ft) not counting the tail (another 14.5 to 30 cm or 5.7 to 12 in) and masses between 3.5 and 18 kg (7.7 to 40 lbs).
These porcupines are nocturnal and herbivorous, but very selective – their favorites are lindens and big tooth aspen. They often get tempted by vegetation at the ends of branches and sometimes, because of their weight, they tend to fall and stab themselves with their own quills. This is why the porcupine is the only North American mammal with antibiotics in its skin.
The North American porcupine’s natural predators include carnivores such as wolves, wolverines, coyotes, jackals and cougars, but they are often avoided as prey because of its quilts.