21 cards where (the text includes “doctor's” and the text includes “companion”) and the color identity ≤ GUW and (the card is available on Paper)

Ace, Fearless Rebel (Doctor Who #98)
Adric, Mathematical Genius (Doctor Who #33)
An Unearthly Child (Doctor Who #35)
Barbara Wright (Doctor Who #14)
Clara Oswald (Doctor Who #9)
Graham O'Brien (Doctor Who #104)
Ian Chesterton (Doctor Who #22)
Jamie McCrimmon (Doctor Who #105)
Jo Grant (Doctor Who #23)
K-9, Mark I (Doctor Who #47)
Leela, Sevateem Warrior (Doctor Who #107)
Martha Jones (Doctor Who #48)
Nardole, Resourceful Cyborg (Doctor Who #50)
Nyssa of Traken (Doctor Who #51)
Peri Brown (Doctor Who #26)
Romana II (Doctor Who #27)
Rose Noble (Secret Lair Drop #1580)
Rose Tyler (Doctor Who #5)
Sarah Jane Smith (Doctor Who #6)
Susan Foreman (Doctor Who #110)
Tegan Jovanka (Doctor Who #28)

In the blink of an eye, they strode from deep snow to the end of this search.