He may only be a tin dog but the death of the third iteration of the Doctor's pet pooch in School Reunion brought a tear to many a child's eye and no doubt a considerable amount of grown up ones, too. It's also a rather triumphant death. The robot was on its last legs anyway and it was given the chance to go out in a blaze of glory. Rose may mock the 'disco' nature of K-9 but there's no one else a time traveller would want in a tight corner and so it proves here, too. Trapped in a school and chased by the Krillitanes, it is ultimately K-9 who comes to the rescue with his trusty blaster. When the Doctor realises that the only way to kill the Krilitane is with their own oil, K-9 works out that his sacrifice is necessary. Not once does he shirk or baulk at the prospect and he even appears to take some enjoyment in baiting the aliens as he wags his tail after being called a 'bad dog'. Sarah Jane's tears sealed the deal and there wasn't a dry eye in the house. Not even the fact the Doctor promptly gave her a younger model could diminish this particular robot's sacrifice. Affirmative! What do you think of this list? Are there any other memorable Doctor Who deaths that we didn't mention? Let us know in the comments below.