Purple Angry Bird
Purple angry birds are very dangerous. They are so dangerous, other Angry Birds become Scaredy Birds should you mention about them to the birds. Originally documented as the "Mutated Yellow Angry Bird"; One of many mutated product species of FEV (fallout) that commonly live throughout the wasteland but recent reports suggest that they thrive mostly in the "goon caves" North and South throughout Japan's Kanto region.
They are believed to have been created by the Umbrella Company to reduce pig livestock after they mutated to multiply like cancer cells and infesting and ingesting the sewer system; bringing famine and disease across Japan. They however only brought upon the birdemic to the Kanto region.
Most people would avoid these purple birds, due to their erratic yet aggressive nature. However, with their most prized almost silk-like feathers and sticky white goo from their abdomen, the local hunters and poachers regularly seek these birds for their livelihood or some profit.