Ponytail

A ponytail was a hairstyle in which the hair was tied back and hung freely from the back of the head.

A ponytail was sported by Rory Williams in a shared dream induced by the Dream Lord, which saw him and Amy Pond living together and uniting with the Eleventh Doctor five years in their personal future. Pointing out Rory's ponytail, the Doctor suggested that Amy hold him down as he cut it off, to which Rory retorted "this from the man in the bow tie". Later, the Dream Lord disparagingly remarked to Amy that the ponytail was what Rory thought the only thing he needed to be interesting. (TV: Amy's Choice)

Worf was seen with a ponytail as he attended the Dæmon Bonjaxx's birthday in his bar on the space station Maruthea. (COMIC: Party Animals)

Giles had a ponytail. (HOMEVID:, PROSE: , etc.)

In non-valid sources
Sashi Kobayashi had two ponytails. (TV: )