Actress Karen Gillan was the primary companion to which Doctor in the science fiction series "Doctor Who"?

Karen Sheila Gillan (born 28 November 1987) is a British actress and filmmaker. Gillan gained recognition for her work in British film and television, particularly for playing Amy Pond, a primary companion to the Eleventh Doctor in the science fiction series "Doctor Who" (2010–2013), for which she received several awards and nominations. She achieved international stardom for portraying Nebula in the Marvel Cinematic Universe superhero films "Guardians of the Galaxy" (2014), "Guardians of the Galaxy Vol. 2" (2017), "Avengers: Infinity War" (2018), and "Avengers: Endgame" (2019).

The Eleventh Doctor is an incarnation of the Doctor, the protagonist of the British Broadcasting Corporation (BBC) science fiction television programme "Doctor Who". He is played by Matt Smith in three series as well as five specials. As with previous incarnations of the Doctor, the character has also appeared in other "Doctor Who" spin-offs.