Mickey Smith is a fictional male Human in the Doctor Who series. The character was portrayed on screen by Noel Clarke. His allegiance / loyalty is to The Nineth Doctor. Mickey Smith is the boyfriend of Rose Tyler, the first person to accompany the Doctor on his return from television wilderness. In the first episode of the return, he long with Rose and the Doctor have to deal with Autons. The Autons are plastic robots controlled by an entity. In the picture below, the Auton version of Mickey gets stuck to a large wheelie bin.
For a large part of Rose Tyler's time as the companion, Rose travels alone but he does join her in ' The Girl in the Fireplace ' and when they get pulled through to another parallel universe within the Multiverse and Parallel Universes / Worlds. In the alternative universe, Mickey is not Mickey but a character called Ricky. There is no Rose Tyler so Ricky doesn't have a girlfriend that we know of. In the alternate universe, Ricky is a bit more confident and aggressive compared to our universe's equivalent. When the Cybermen rise, Ricky is one of the defence leaders.
During the fighting, Ricky is killed by a Cyberman and Mickey takes Rickys place to ensure that the fight against the Cybermen continues. When the fight is over, Mickey decides to stay in the alternate universe because his grandma is alive in that universe where she is dead in ours. He has no one in this universe and he misses his gran.
During the Battle of Canary Wharf, Mickey and Jake, a friend of his from the alternate universe are able to pull through to our universe in order to carry on the fight that is now set to engulf our planet.
At the end of the last episode of David Tennant as the Doctor, the Doctor visits Mickey Smith one last time on a battlefield. With Mickey Smith is his wife, Martha Jones, how they got together and became husband and wife is not explained.