Jack Kirby was a man involved with American comics.
While in his TARDIS, the Eighth Doctor read "Jack Kirby" comics. (PROSE: The Wickerwork Man)
Panda once mentioned Jack Kirby. (AUDIO: The Iris Wildthyme Appreciation Society)
When the Twelfth Doctor showed Jess Collins The Hay Wain and heaped praise upon its artist, John Constable, Jess' brother Maxwell quietly said that "[he was] no Jack Kirby". (COMIC: Bloodsport)