After first meeting the Doctor when she was seven, Amy Pond (Karen Gillan) thought for years he was an imaginary friend. Until he showed up again the day before her wedding and it turned out her Raggedy Doctor was really an alien Time Lord (tangentially, what is up with the Doctor and redheads’ weddings?).

Time agent, conman, companion – Jack Harkness has been all of that and more over the course of his long, strange life. If he’s not off adventuring with the Doctor, this omnisexual, immortal flirt can be found running the Torchwood Institute on Earth, defending the planet when the Doctor can’t.

Originally a Viking child encountered by the 12th Doctor on the BBC series Doctor Who, Ashildr (Maisie Williams) became immortal after the Doctor resurrected her from death. She took advantage of her immortality, traveling the world and assuming many aliases – so many that she eventually took the simple name “Me”. She lives to the end of time and then, due to the wonderfully pliable time laws of Doctor Who, encounters the Doctor once again. This is for her outfit in the episode ‘Face the Raven’, when she is mayor of a London town inhabited by aliens. For the tattoos, use body paint or a handy eyeliner pencil.

Rose started out as a normal nineteen-year-old shopgirl until the Doctor blew up her shop (there were Autons inside at the time – don’t ask). But given the choice between an ordinary life and adventure through all of time and space, Rose chose the latter. Hey, who wouldn’t?

Companion to The 10th Doctor, med student Martha Jones didn’t exactly expect her life to be interrupted by an alien in a blue box. Nor did she realize following him on a whim would lead her on a universe-spanning adventure and give her the skills to save the entire world.

A companion of the 12th Doctor on the BBC TV series Doctor Who, Bill Potts (Pearl Mackie) begins as a student of the Doctor before learning his time-traveling secret. After she agrees to travel with him and his other companion Nardole, she sets out on a series of adventures. Fans love her as a smart, lovable, down-to-earth, sassy woman and the first lesbian portrayed on the show.