K-9 is a robotic dog on Doctor Who. He’s most famous as a companion to the Fourth Doctor, though he did make an appearance with the Tenth Doctor in the 2006 episode “School Reunion.”
K-9 addressed the Doctor as “Master,” which inspired this digital image by DeviantART member madaigual. K-9 listens attentively to the wind-up gramophone, just like the dog in Francis Barraud’s painting “His Master’s Voice.” Several sound equipment and record companies have used that image as a trademark since 1900.