The Assistants

Along with the Doctor's companions, he meets some people along the way who assist him in the role of a companion, but only for an episode or a few episodes. Here you can find articles on them.

Katarina
Sara Kingdom
Harry Sullivan
Kamelion
Pete Tyler
Sally Sparrow
Astrid Peth
Jackson Lake
Christina de Souza
Adelaide Brooke
Wilfred Mott
Canton Everett Delaware III