Punk ponies are as the name suggests, ponies who are fans of punk rock music and dress accordingly as such.
Origin and spread
Punk ponies often have their hair spiked up, mohecan style or just in muti-colours (this ocassionally gets Rainbow dash confused for a punk pony), however there are some that have glam metal style fuzzy hair (similar to Maxx Powers) or just long hair in general typical of heavy metal fans.
Typical attire consists mostly of leather jackets, aviatior glasses, airpony jackets, shin high boots, many piercings, headbands in fact anything related to punk/metal fashion is probably in there somewhere.
Controversy and negative views
Punk ponies are often described/depicted as being rebellious hellraisers, constantly looking for trouble