K9 Mark IV - list of appearances

Series 2

 * School Reunion (introduction; cameo)

Series 4

 * Journey's End

Series 1

 * Invasion of the Bane
 * The Lost Boy

Mini-episodes

 * From Raxacoricofallapatorius With Love

Series 3

 * The Mad Woman in the Attic
 * The Wedding of Sarah Jane Smith
 * Mona Lisa's Revenge (living drawing; part two only)
 * The Gift

Series 4

 * The Nightmare Man
 * Death of the Doctor (flashback; archive footage; part two only)
 * Goodbye, Sarah Jane Smith (part two only)

The Sarah Jane Adventures novelisations

 * Invasion of the Bane
 * The Lost Boy
 * The Wedding of Sarah Jane Smith

Find Your Fate series

 * Search for the Doctor

Short stories

 * A Dog's Life