The Tenth Doctor, as portrayed by David Tennant, featured in seasons 2-4 of Current Who.
The Ninth Doctor (Christopher Eccleston) regenerated after absorbing the energy of the TARDIS from Rose (and no one's supposed to do that).
The Tenth Doctor (David Tennant) regenerated into the Eleventh (Matt Smith) after absorbing radiation poisoning.
(Apparently the radiation absorbed during Smith and Jones was not deadly.)
Rose Tyler (Billie Piper) was the Doctor's companion through Season 2, having met him earlier (in Season 1). He left her on the beach in Norway before they met again to defeat the Daleks.
Martha Jones (Freema Ageyman) was the Doctor's companion throughout the seasons, having met him in the hospital in the episode Smith and Jones (Season 3, Ep. 1).
Donna Noble (Catherine Tate) was the Doctor's companion beginning in Season 4. They met originally in the Christmas Special of Season 2, The Runaway Bride (Season 2, Ep. 14), parted ways, and then met again in Partners in Crime (Season 4, Ep. 1).
Upon the defeat of the Daleks, Donna, who had absorbed too much of the Doctor's knowledge and power, had her memory wiped by the Doctor in order to save her life.
Main Villains BattledEdit
Dalek - the most dangerous villain in perhaps the whole series, the Daleks were exterminated by Captain Jack Harkness, Martha, the Doctor, Rose, and other companions working together.
Host - in the episode Voyage of the Damned (Season 3, Ep. 14), the Host were a league of "informative" angels ordered to kill everyone aboard the space liner Titanic after the TARDIS collided with the ship and the ship's captain sabotaged the liner.
Rachnoss - in The Runaway Bride (Season 2, Ep. 14), upon Donna's arrival in the TARDIS, it was discovered that she had been absorbing large amounts of Huon particles. This led the Doctor and Donna to the Rachnoss, which were trying to rebuild themselves on the Earth after their destruction.
Weeping angels- Stone- only when you see them- the moment you look away BOOM they move. They appear in "Blink" (Season 2 ep. ?)
- Allons-y ("let's go" in French)
- Wibbly wobbly timey wimey
- I hate pears
- I just want a mate