Tom and Jerry

Tom and Jerry was a cartoon on Earth.

Toshiko Sato told Ianto Jones that she had worked with mice long enough to know that their love of cheese was a cliché born out of old Tom and Jerry cartoons. (PROSE: Slow Decay)

Information from invalid sources
After the Doctor regenerated into his seventh incarnation, both he and Peri Brown decided to look into the TARDIS scanner on where they landed, but one of the channels was stuck with a Tom and Jerry cartoon, featuring a cat and a mouse. (TV: Untitled)

Other matters
John DiMaggio, Tara Strong, Rachael MacFarlane, Kari Wahlgren, Robin Atkin Downes, and Wayne Knight have all had voice roles in various pieces of Tom & Jerry media.

Tom and Jerry appeared on the covers of several TV Comic annuals which also printed Doctor Who content. This includes TV Comic Annual 1971, TV Comic Annual 1975, and TV Comic Annual 1978.