Here's the complete list of pony breeds and their PI stats. PI was kind enough to supply base Strength, Intelligence, Agility, and Charisma scores for all of their breeds; which track pretty well to potential D&D bonuses-- except that WIS and CON are out in the cold. I'm going to attempt to convert the stats given for each race into reasonable bonuses based on a) the PI base stats as much as possible, and b) expected 4e classes. All ponies will be medium sized creatures, and there are some races, that while I list them here for completeness, I'm likely to leave out of the final conversion (ie, all of the aquatic breeds). Anyway, if you would like to read the descriptions that I'm going to be working with, you can look here
Earth Pony (your basic, no-frills pony): [IN: 7 | ST: 10 | AG: 6 | CH: 7]
Flutter Pony (flier): [IN: 5 | ST: 5 | AG: 12 | CH: 8]
Pegasus Pony (flier): [IN: 7 | ST: 8 | AG: 5 | CH: 10]
Unicorn: [IN: 11 | ST: 5 | AG: 5 | CH: 9]
Fairy Pony (flier): [IN: 6 | ST: 3 | AG: 9 | CH: 12]
Dragon Pony: [IN: 12 | ST: 12 | AG: 8 | CH: 2]
Winged Unicorn (flier): [IN: 11 | ST: 8 | AG: 5 | CH: 10]
Wishing Pony (flier): [IN: 12 | ST: 5 | AG: 8 | CH: 15]
Valkyrie: [IN: 13 | ST: 6 | AG: 13 | CH: 2]
PhoenixPony: [IN: 8 | ST: 4 | AG: 12 | CH: 10]
Kirin: [IN: 14 | ST: 6 | AG: 6 | CH: 12]
Purr Pony: [IN: 9 | ST: 9 | AG: 14 | CH: 8]
Reindeer Pony: [IN: 9 | ST: 5 | AG: 13 | CH: 13]
Mountain Pony (flier): [IN: 6 | ST: 13 | AG: 13 | CH: 8]
Aquatic ponies, either left out or for another type of campaign:
SeaPony: [IN: 6 | ST: 6 | AG: 10 | CH: 8]
ShellPony: [IN: 8 | ST: 12 | AG: 4 | CH: 6]
MerPony: [IN: 8 | ST: 4 | AG: 11 | CH: 10]
MerDragon (flier) : [IN: 10 | ST: 10 | AG: 10 | CH: 10]
Right out of the gate, we've got an issue with with fliers, because the ability to fly is Just Plain Better. Although this is a subject of considerable obnoxious debate, Fly speeds are the shit, as are potentially avoiding attacks of opportunity by flying over someone's head. Also, the chance of making the game just unplayable for non-flying PC characters, because they can't follow their flier friends, is a worry. There are certain types of campaigns that you can have with a party of fliers that you have a harder time with, using non-fliers. Earth Ponies are pretty much the humans of the world, and making them competitive will be something of a trick.
Secondly, there's how nothing in D&D is really designed for quadrupeds. I am getting around that by assuming that a Pony Game would be ponies only, and so all armor/items/etc exist in a pony-friendly version. This will be harder to justify for weapons like swords, axes, bows & crossbows, et al, unless they are mounted on the armor somehow. Ponies have the advantage of having things like hooves, teeth, and (in some cases) horns, which can be easily weaponized. Anyway, I'll deal with Pony Itemization in a later post.
I'll be using some of the ideas and versions of the powers shown for the Gritaur, here. Specifically, I am thinking I will grant flying races the following power (modified from Sabelkatten's Gritaur racial of the same name):
Take Wing Flying Pony Racial Power
With a powerful thrust of your wings you launch into the air to find a better spot from which to engage your enemies.
Move Action Personal
Effect: Until the end of your turn you may fly your speed +2. If you don't end your turn on solid ground, you glide to the ground without taking falling damage.
So to begin with, I'm just going to list some preliminary bonuses-- yes, I'm giving everyone an option for at least one stat. Because I believe strongly in that, and there's some classes I want to allow for certain. Though I'm not really speccing for Essentials, because I don't know enough about them, and because I'm not all that impressed with what I do know. Also, the... notes that Pony Island includes about the races. Paraphrased. Yeah.
Stat bonuses: +2 to any one stat, extra feat at first level.-- yep, these guys are humans. What do you want?
I am toying with the idea of making it easier to buff them, or giving them an extra bonus from buffs cast by their allies, but hm. Apart from that, they have the normal human abilities and bonuses.
Flutter Pony (flier)
Stat Bonuses: +2 Dex, +2 CHA or CON
These guys are supposed to be "the most agile of all the breeds," so dex was a no-brainer here. Of course, this was also subverted when the Purr Ponies came out a few years later, with their 2 pt higher AG than the Flutters have. Smooth moves, guys. They're supposed to be a little ADHD (movement based), which says to me Monks and shifty-styles Assassins, though their supposed flakiness and weakness puts the kabosh on getting you Wisdom or Strength. Certain rogue builds are all right here. These guys also get my first stab at a Racial Power, based on having watched the My Little Pony Movie a few too many times as a kid:
Racial Power: Shift to Utter Flutter
Encounter, minor action
The flutter pony beats its wings rapidly, creating an arcane wind to blow away unnatural phenomena.
Effect: Move a zone created by an enemy up to 5 squares.
Pegasus Pony (flier):
Stat Bonuses: +2 WIS, +2 CON or STR
These guys don't have much going for them in PI, compared to later breeds, but that's all right. They're supposed to be "strong fliers," so they may get longer flight times before other races, depending on how much that'll unbalance things. I waffled some on CHA as opposed to WIS, but CON is really more what I ought to consider switching, if, say, I want these guys to be paladins, though they're not horrible for it. As is, I like them for Wardens pretty well.
Stat Bonuses +2 INT or CON, +2 WIS
This does some odd things-- like making Artificer totally a Unicorn favored class. I was seriously tempted to give them Dex or CHA, so one could play a unicorn assassin, because Unicorns are total bastards in the Overlord games (and in the original MLP show, just fyi). Though PI ponies are intellectual types, so the idea is that they should be good for arcane classes. Which is what happens when INT is a primary stat, right?
I'm also tempted to give them some sort of teleportation racial, based on the My Little Pony show, in part to compete with the flying ponies.
Fairy Pony (flier):
Stat Bonuses: +2 CHA, +2 DEX or WIS
Fairies are supposed to be the smallest and weakest, and their PI strength score is the lowest score of ANY in the game. In the 3.5 thread, the OP made them small creatures, but Kainenchen says nothanks to that, at least on their base size. I may rethink their stats and make the WIS option an INT option, so that Sorceror and Warlock are both reasonable options, but I dunno.
Dragon Pony (flier?):
Stat Bonuses: +2 STR, +2 CON or CHA
So these guys are Dragonborn, except PI tanked their CHA, which is a thing I am fixing. Because they're Dragonborn, and will have pretty much the Dragonborn racials. They do have wings in the PI version, but I haven't decided if I want to have them be fliers yet.
Winged Unicorn (flier): [IN: 11 | ST: 8 | AG: 5 | CH: 10]
+2 INT, +2 CHA or ST
Here are my CHA/INT folks, which makes them... kind-of Tieflings? Hrm. They are set up ok for Warlocks, or Warlords, I think, though in the case of the latter you want STR, in the first you'd want CHA. Other than that, there's not much about these guys apart from, "well, they're unicorn/peg. half-breeds. I don't know what you wanted there." Incidentally, I will probably consider Racials that are similar to half elves for them.
Wishing Pony (flier):
+2 CHA or INT, +2 DEX or WIS
Unicorn/Fairy crossbreeds, these guys have huge, delicate, flipperty butterfly wings and are totally meant to be from somewhere divine. So I wanted to make them easy for almost any divine source class to play. Clerics, Avengers, and Wis/Int Invokers spring immediately to mind.
+2 STR or CON, + INT or DEX
These dudes are supposed to be fiery badasses, though their cha and strength are tanked in PI stats. I may futz around with their stats more, because while they'll make good assassins or fighters as-is, I kind of want them to be good Avengers too, for which they should really be able to be Dex/Int. I could switch STR and INT, I suppose. Hrm.
Also, I am not sure what I want to do for their racial; fire resistance is necessary, but powers? Not sure yet. Will consider more.
+2 DEX, +2 CHA or STR
One of my favorite breeds. Set up to be good fighters, sorcerers, and rogues, at the very least. PI says that, "their magical tears can heal almost any wound," which implies that I ought to make them good leaders and give them a healz-stylez racial, though the other option is giving them some sort of on-0-hitpoints effect. Because, well... phoenix. At the moment, they could be uh... Cha/Str Clerics, I guess? Or Paladins. Which I like. Switching Dex or Cha to Wis is not impossible though, I suppose. Will also merit more thought.
+2 INT or DEX, +2 CON
My definite favorite breed. These guys will have racials that are some sort of natural armor bonus, because of awesome scales. Also set up to be assassins (why do I seem to think that all ponies should be assassins?), and... looking down the list, um, so are the next couple of breeds. Fook. Maybe I will change the dex to CHA or STR, because these guys also should be able to play Pallies. Hrm hrm.
+2 Dex, +2 STR or CHA
Rogue? Rogue. Was going to make CHA potentially CON, but no. Rogues. For serious. Which means that there are still assassin builds these dudes are good for.
What is a Purr Pony, you ask? Well, it's a half-cat, half pony. Also, it is the breed that makes Shieldhaven's eyes most prone to rolling out of his head with the sheer ridiculous. Well, it is pretty ridiculous. But still. Shaddup.
+2 DEX or CHA, +2CON or STR
These guys are, well, the Christmas breed of PI, and are exactly what they say. STR is supposed to be tanked for them, but... um, antlers? Come on now.
Also, I am not giving them a magical flight power, because there are levels of silly that confound even me.
Mountain Pony (flier):
+2 STR, +2 DEX or CON
Big, shaggy ponies with 2 sets of wings. Probably going to give them some sort of wing-buffet stun power as a racial-- one turn, not save ends. This will actually get better for them at paragon, when at least that ensures that bad guys take the status for a whole round, instead of shrugging it off on their turn. But these guys are the ones I'd play if I wanted to do, say, a grappling fighter. Still not sure about the dex, because of how big they are, but I'm serving more the classes I want to see, rather than, well... simulationism.
Let this be her character note.
Also, you may wish to live in fear, because there will be more posts on this subject.
Sorry about that, to both of you reading out there.