9. Accidentally Fell Into Acid (Vengeance On Varos)
The Doctor seems strongly committed to their "no killing" rule these days, but that doesn't mean the Time Lord hasn't shed some blood over the years.
An adventure for Colin Baker's Sixth Doctor, Vengeance on Varos was first transmitted in 1985, and saw the Doctor and companion Peri stuck on a world where torture and executions were broadcast for mass entertainment.
However, the viewing public of Varos got more than they bargained for when two guards accidentally fell into a vat of acid while trying to dispose of the Doctor's body.
The Doctor - who isn't actually dead - pops up and startles one of them, which sends them falling into the bubbling brew. Then, after a brief scuffle, the other guard gets pulled into the acid bath as well.
The first death here is utterly ludicrous. The Doctor taps the guard on the shoulder, which makes him jump, sending his colleague face-first into the vat. All it needed was a wacky sound effect and it would've been straight out of a farce.
He might have murdered two innocent men for simply doing their jobs, but we'll let Colin off the hook this time because it was so damn funny.