In a show where literally anything can happen, it's no surprise that the writers of Doctor Who have imbued several characters with immortality over the years.
Whether through lack of aging, an ability to withstand fatal wounds, or simply just being an eternal creature from the dawn of the universe, cheating death is a common occurrence in this show, which certainly comes in handy when you've got trigger-happy, warmongering aliens like the Daleks, the Cyberman, and the Sontarans blasting the universe to shreds every five minutes.
And that's not to mention all those destroyed planets and apocalyptic events. In Doctor Who, that's basically an average Tuesday.
From Captain Jack Harkness' remarkable ability to survive any sort of injury thrown his way, to a magic elixir that grants the drinker some of that sweet, sweet eternal life, to one of those pesky curses that forces you to live out the rest of your everlasting days in constant agony, an inability to die is a fairly attainable trait in the Whoniverse - as these ten characters have demonstrated time and time again.
10. The Family Of Blood
Immortality sounds like a blast on paper, but in practice... potentially not. The Family of Blood learned that the hard way in Series 3, with the Tenth Doctor trapping each of the four members in some increasingly dark, everlasting situations.
The Father was wrapped in unbreakable chains and imprisoned; the Mother was tricked into the event horizon of a collapsing galaxy; the Daughter was trapped in every mirror in existence; and the Son was suspended in time while dressed as a scarecrow, left to watch over the fields of England.
It's chilling stuff, but on the plus side, the Family's primary goal was to become immortal. So, technically, the Doctor granted their wish. It's not his fault that they didn't specify exactly what they wanted their eternal fates to look like!
While the Daughter was freed by the Thirteenth Doctor in a lockdown webcast written by Paul Cornell (the writer of the original episode), the canonicity of that story is up for debate. In terms of the actual show, each member of the Family is presumably still trapped in their grisly scenario - so it's possible that the Doctor could revisit them one day. And who wouldn't want to see that rematch?