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.

Peter Capaldi is the 12th incarnation of Doctor Who, accompanied by companion Bill. In the 10th series of Doctor Who, his costume has changed from a navy coat with red lining to a black coat with blue lining.

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?).

Change is good. The 11th Doctor knows this. That’s why he wears a bowtie now. Bowties are cool. And sure, his regeneration was a little rocky and maybe the TARDIS needed a new desktop theme anyway, but he’s got everything under control. Really. You can stop laughing at any time.

The Fourth Doctor (Tom Baker) is the most tenured and iconic Doctor Who, lasting seven seasons before his transformation. He’s instantly recognizable by his curly brown hair, eyes that constantly boggle, and of course his impractically long multi-colored scarf.

The endearing, cowardly Nardole (Matt Lucas) was a brief companion of the 12th Doctor on the BBC TV series Doctor Who. Originally an employee of the Doctor’s wife, River Song, Nardole lost his head in an attempt to discover River’s whereabouts but was reassembled by the Doctor. The two joined forces for a short while, and then Nardole made a courageous decision that lead him down a different path. Nardole dresses in a distinctive, goofy outfit of burnt orange coat, beanie and glasses.