Slipknot Ponytail/Sandbox

If a character has long hair tied in a ponytail there is a chance that the hair will become undone during a fight or action scene. The probability of this to happen increases with the intensity of the situation and the challenge the opponent poses. Of course, this isn't restricted to ponytails alone. Braids, twintails, hair loopies, and other hairstyles just begging to get undone while in the heat of battle also count.

It serves to give the character an instantly rougher, more primal and Badass look that can underscore the seriousness or desperation of the situation. On the other hand, unbound hair can also create a vulnerable look. In classical Japanese paintings defeated Samurai were often shown with messy or disheveled hair, so naturally many Anime characters end up looking like this when things are getting rough. Sometimes it is used to make a character that much hotter while fighting, especially in combination with Clothing Damage.

Compare Close-Call Haircut. If the ponytail gets severed completely, it easily becomes a Traumatic Haircut and possibly an Important Haircut.