@Background Pony #9AA9
That’s 6 you fool.

The 5th Doctor was ruthless and violent.

@deyogee  
Still black hair very visible beneath the blond which makes him look very different from your average blond head. On top of that, add the stubble.
 
 

 
While Perfect Pace looks every bit as much like Five as Doctor Whooves looks like Ten. (Except the blue coat, but neither time lord wears blue.)

@Phantom Rider  
Apologies for the necropost, but people don’t usually mean Season 3 Master when they say Perfect Pace resembles him, they mean the Master during the specials when he has blond hair.  

 
But he certainly resembles Davison as well! I suppose it’s all a matter of preference.

Thing about Perfect Pace being the Master is… there’s zero resemblance.
 
No, really. You’re lookin’ at Perfect Pace right now, and this is the Master:
 

 
Resemblance: nil.
 
But, on the other hand, Peter Davison’s Doctor:
 

 
Light clothing = light coat. Collar, check. Five didn’t wear a bowtie, but the color of his shirt means there’s plenty of red at the neck. Blond hair: Check. Parted the same way? Well, Davison’s not dead-center like Perfect Pace but still, both characters have this nice big notch. You can totally see half of Perfect Pace’s head like so:
 

 
So yeah. No doubt who he looks more like here! If the makers of the trading cards disagree, then they’re blind too, ‘cause he still looks everything like Five and nothing like the Master. The real mystery isn’t who he’s supposed to be, it’s how anyone ever thought he looked more like the guy at the top than the guy at the bottom.
 
If I had to guess… not everyone knows what the old series characters look like offhand - even if you’ve Googled the past doctors it’s not burned into your head unless you really spent some quality time the old stories and came to love them. And  
of the old Doctors, Five is considered one of the least distinctive; the others hammed it up while he’s more low-key. Between the legend that is Four and the hot-tempered brightly-colored Six comes a guy who was low in the bombast department, so he’s often forgotten.
 
So then FIM comes and we spot a pony who looks just like Ten and has an hourglass cutie mark of all things. And the Master is one of the most beloved Who villains, new series or old. So the first pony who isn’t Doctor Whooves and who has an hourglass cutie mark appears. Who are people gonna instantly label him as? Not the most forgotten of those who portrayed the Doctor in decades past. But which Time Lord Perfect Pace actually resembles is clear.
 
I hope someday they make a pony who really does look like the John Simm Master. I guess we have a decent fit for Michelle Gomez’s Master, though:
 

 
But I’ve also seen that pony with a gavel cutie mark and her nicknames being Lady Justice or sometimes Swift Justice leads me to believe that she probably has it more often than the hourglass - I could be wrong, never really noticed her around. But… sometimes she has an hourglass and she does have some things in common with Missy (unlike Perfect Pace and the John Simm Master.) so… say something nice!
 
(Mods and such, sorry to abuse the imbed image feature like this. I promise it won’t become a habit.)

Is there a version of the 12th Doctor? You know, the one who keeps on saying fuck!

The “Fifth” was long ago named as “Perfect Pace, time master” and confirmed as being The Master disguised as a normal pony.