
Alice O'Donnell's ponytail. (TV: Before the Flood)
A ponytail was a hairstyle in which the hair was tied back and hung freely from the back of the head.
Clara Oswald sometimes had her brunette hair in a ponytail. (TV: Cold War, The Zygon Inversion/The Zygon Invasion)
Alice O'Donnell wore a ponytail. (TV: Before the Flood)
Martha Jones wore her hair in a ponytail. (TV: Smith and Jones, The Shakespeare Code, Gridlock, Daleks in Manhattan|Evolution of the Daleks, The Lazarus Experiment, 42, Utopia, The Sound of Drums, The Sontaran Stratagem|The Poison Sky, The Doctor's Daughter)
Yasmin Khan wore a braided ponytail when she left the Thirteenth Doctor after the Master's Dalek Plan. (TV: The Power of the Doctor)
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: When to Die [+]Bill Baggs, P.R.O.B.E. video stories (BBV Productions, 2015)., PROSE: Silver-Tongued Liars [+]James Wylder, Cyberon (Arcbeatle Press, 2020)., etc.)
Behind the scenes[]
In non-valid sources[]

Sashi Kobayashi. (TV: Untitled [+]Disney XD promotional videos Disney XD promotional video (Disney XD, 2015).)
Sashi Kobayashi had two ponytails. (TV: Untitled [+]Disney XD promotional videos Disney XD promotional video (Disney XD, 2015).)