Right so first and foremost I'm going to be honest and admit I'm a HUGE Doctor Who fan, right just had to say that. So for those who don't know what I'm on about The Doctor is a alien from the planet Gallifrey with two beating hearts. The doctor have the ability to regenerate (if body damage, wearing thin he can change his appearance completely) he travel in a blue police bow called the TARDIS (Time And Relative Dimension In Space)
(For 12th Doctor see Clara Oswald) his companions travel with him to see the wonders of the universe and in return for seeing the stars the doctor ask his companions to be his friend,stay with him and remind him now and again why he chose the name the doctor to help people. They include Rose, Martha, Donna, Clara, Captain Jack Harkness, Sarah Jane Smith, Amy and Rory.
Enemies. The Doctor have many enemies but the most famous are -
From the planet Skaro and is perhaps the only enemy the doctor fears the most, not only the enemy of the doctor but also his people the timelords.
Basically humans in a suit with no brain at all to feel emotions and their main objective is to convert all humans to be like them.
An enemy bit closer to home for the doctor, once a childhood friend to the doctor he grew up he'll bent on immortality and ruling the universe. A thorn in the doctor side ever since they both stole a tardis to go off and explore the universe.
One of the oldest races in the universe, one of the most powerful advanced races in the universe. Their origin is unknown but their deaths came at the hand of the doctor during the battle with the Darleks during the time war. They were saved by the doctor but in another universe though.
Family ) the doctor is sorta married (kinda) to a fellow timelord River Song who parents are Amy Pond and Rory Williams, he have a daughter name Jenny and a granddaughter named Susan