Second Doctor
The Second Doctor is an incarnation of the Doctor, the protagonist of the BBC science fiction television series "Doctor Who". He was portrayed by character actor Patrick Troughton.
David Tennant
Tennant featured as the Doctor in an animated version of "Doctor Who" for "Totally Doctor Who", "The Infinite Quest", which aired on CBBC. He also starred as the Doctor in another animated six-part "Doctor Who" series, "Dreamland". Tennant guest starred as the Doctor in a two-part story in "Doctor Who" spin-off "The Sarah Jane Adventures", broadcast in October 2009. He continued to play the Tenth Doctor into the revived programme's fourth series in 2008. However, on 29 October 2008, he announced that he would be stepping down from the role after three full series. He played the Doctor in four special episodes in 2009, before his final episode aired on 1 January 2010, where he was replaced by the eleventh doctor, portrayed by Matt Smith. The "Daily Mirror" reported that Tennant was forbidden from attending "Doctor Who" fan conventions while playing the role, to avoid the chance that he could accidentally let slip any plot points during filming of the series. However, Tennant claimed this was false and that he had never been banned or discouraged from attending conventions.