@Ichijoe
 
Twilight might be a good match in terms of intelligence to be Marvin.
 
 
Not many terminally depressed ponies, though.

So Pinkie is Zaphod, would this make A.J. Arthur? And more to a point who’d make the best Marvin? Lets rule out Spike as an easy Pick we need to think of somepony else. what about Flutterbitch? That got board of being bitchy all the time?

Ok I got it mixed up I kinda thought those “Books” ran along the same idea.  
But, I’ll admit that I never read them and that I have almost no intention to do so either.
 
It’s kinda like Bob Ross re-painting the Mona Leisa, only not as epic ’cause no Ones ever heard of the Cat that wrote those Books.

@Ichijoe  
Wasn’t talking about “Salmon of a Doubt”. I was talking about “And Another Thing…” written post-mortem by Eoin Colfer.

@Ichijoe
 
Oops… Five appendages.
 
Sorry about that.

@ze
 
I know, I was just joking, sheesh.
 
And also #Ichijoe , neither pinkie here nor zaphod has 5 arms, because pinkie has 5 legs.  
She has three front legs because ponies use them much the same as we use our arms.

Heresy the there is no “Sixth Book” Adams only ever wrote Five Books. “A Salmon of Doubt” is not and will never be canon IMHO, it was a cheap cash-in for Adams estate (mores the pitty for Mr. Adams!), and the cat that actually wrote it.  
I’m no fan of Mostly Harmless, but at least it did put an end to it. An end that Mr. Adams was probably grateful for as well…

VV FIVE ARMS ARE YOU FREAKING NUTS!  
Zaphod only ever had the Two Arms PLUS the One cause he wanted to take up Ski Boxing. (i.e. He only ever had the Two Heads and the Three Arms!)
 
Damn don’t you People bother to read the Classics anymore?

This has been another pointless and overly informative comment by Ze. Please don’t forget to pay your taxes.

@sixtyfour215  
The five legs are a reference to Zaphod Beeblebrox, President of the Galaxy, the character that Pinkie Pie is depicted as in this picture.
 
Zaphod has five arms and two heads. This picture depicts Pinkie with one head, unlike what is seen in the TV show. In the motion picture, however, Zaphod’s second head flips up from under his neck and is hidden mostly by a scarf. The scarf shown in this picture does not seem to be able to hide a head in the way that the movie’s scarf was able to.
 
Zaphod’s second “smarter” head did get separated from the rest of Zaphod in the sixth book of the trilogy, however, this event should not be taken too seriously, as the sixth book takes place after the Earth is blown up an infinite number of times, all the main characters appear to be killed (except Zaphod) and, most importantly, the author died from a heart attack. Despite all this, the sixth book was written and published, for better or for worse.
 
Actually, nothing in the Hitchhiker’s trilogy should be taken seriously, especially the claim that it’s a trilogy.

@donut64s  

I read that book. Didn’t like it.

…Her drinking a pangalatic gargleblaster… TIME TO PANIC

Pinkie is one hoopy frood!

Hey pinkie, pass me a pangalactic gargleblaster wouldya? Thanks!

i’m not panicing.
 
Wait, does she have 5 legs!?!
 
panics!