I don't think anyone's really explored the idea of how the mane eight (including Spike and Starlight) would be when it comes to the idea of diapering up and being an AB (or AF if you prefer)/DL. There's maybe been some on other padded groups for the mane six, but none for the mane eight. So let's fix that now. I'll be starting off with how I'd rank them from least likely to be padded to most likely to be padded, based on my observations of them as characters. But it's not official, so you can disagree so long as you respect my opinion.

8. Spike: Spike has pretty much hated being called a BABY dragon, and treated like he's just a little kid. He's always wanted to be seen as more mature, someone equal to the girls, and someone to be treated with respect. Considering how much he has matured over the seasons, to where he is pretty much the voice of reason for not only Twilight, but also Starlight and even sometimes Discord, I can't particularly imagine he'd like the idea of being a baby again, even just for a little while. If he ever did pad up, it would be either because he was tricked into it, or because of problems controlling his bodily functions (assuming his body ever started to grow without the use of greed).

7. Rarity: Out of the ponies of the group, Rarity is perhaps the most mature, at least in terms of emotional development and behavior. She runs her own business, and manages two more successful shops with business partners, plus she has displayed saint like patience with her little sister Sweetie Belle, and even the likes of Sassy Saddles and the Diamond Dogs, not to mention Prince Blueblood. While she does still sometimes think romance should play out like a fairytale, and has a tendency to break down in tears, she tends to be a lot more composed and strong willed compared to her friends. But Rarity has shown that she is still very much opposed to the idea of doing anything dirty or "uncouth", and I could easily imagine she'd view AB/DL in the same way. At best she'd be a caretaker for someone else, and even then she would need a lot of time to accept the idea. If she did pad up, I'd imagine it would only be for long fashion projects where bathroom breaks are an incovninence. It would take a lot just for her to even get used to the idea of wearing a diaper, let alone the thought of using it for its intended purpose.

6. Applejack: Applejack would more firmly be suited as a caretaker, even though she's not the greatest at it compared to Rarity. The way I see it, Applejack is very much like a kid who was forced to grow up before their time, she misses the simpler days and clings onto the past to convince herself that everything is okay, but at the same time she knows she can't go back, that the more she tries to hold onto the past, the more things change. Her workaholic behavior would make her feel guilty about taking even just a day off to be a foal again, even if she were assured that others could fill in for her and everything would be okay. Yes, losing your parents at a young age can be a driving force for one to want to revisit their early childhood, to cope with the pain and feel like it hasn't happened. But Applejack just wouldn't be able to bring herself to do it voluntarily. If she padded up, it would be solely for work related purposes at first (or an injury that damaged control of her bodily functions). You'd have to really keep pushing to get her to accept the idea of being an AB/DL.

5. Rainbow Dash: I specifically waited to make this thread until "Parental Glideance" aired here in the U.S., so that I could properly judge Rainbow Dash's past and how she is now. I think it's clear to say that, with the exception of Twilight and Fluttershy, Rainbow Dash had the most straightforward childhood out of all her friends. It wouldn't surprise me if her parents practically smothered her with affection from the day she was born, especially seeing as they kept the diaper she was in when she spoke her first word. While it's clear that this drove Rainbow Dash to be the best at everything, and outshine the competition, it's also clear that she eventually grew tired of it when it didn't stop after she started winning all the time. As a result, I don't think Rainbow Dash would be all that keen on revisiting her childhood. She may possibly be a closest AB/DL for the sake of relaxation, depending on how lazy she might feel, but she would be very cautious about doing it, and would take great care to ensure nopony ever suspected her involvement.

4. Fluttershy: Fluttershy is kind of hard to pin down, because she's cute either way. Cute as a baby, and cute as a caretaker. Her personality lends itself well to caretaker roles (outside of "Pattycakes" and "Pattycakes 2"), and I don't think it's a surprise that she gets featured in a lot of padded fics in the caretaker role. But even though she has recently displayed significant growth as a caretaker and has been willing to stand up for herself when need be, I can imagine she might still want to seek comfort and security, and padding up might be her way of doing so. Fluttershy is probably what most AB/DLs are actually like, they want to relax and be cared for, but they don't want to completely regress and lose all their adult responsibilities. For them, they want a good balance, a chance to feel young and cared for again, but knowing full well that they can return to being a productive adult whenever they want to.

3. Starlight Glimmer: Probably the hardest to really say for sure, given how little we know about her family and past. But much like Applejack, Starlight's childhood trauma could be a motivator for her to want to reclaim her childhood, return to a more innocent and carefree time that she was robbed of enjoying. In a lot of ways, Starlight still acts like something of a child, as rather than confront the problem head on she tries to seek comfort in what she knows, even though that tends to make the problem worse. What few padded pony works there have been that feature her, I think Starlight has shown that she can lend herself well to this genre of fanfics. If we knew more about her past and what kind of family she had, maybe she'd be higher or lower.

2. Twilight Sparkle: Though she seems to have gotten a little bit better at dealing with it, Twilight still doesn't do well when stressed out, and if "Look Before You Sleep" and "Amending Fences" is any indication, Twilight may have wanted to have a social life with friends that she ultimately didn't get to enjoy with her pursuit of knowledge. The fact that she kept Smarty Pants, which was her favorite toy as a filly, looking past how old and beat up it was (and the accessories it came with), I think that says a lot about how Twilight viewed her childhood. That even after moving to Ponyville, she wasn't fully ready to leave it behind for good. And with her neruotic tendencies and still occasional hint of OCD, I could see Twilight getting into AB/DL to help her calm down and maybe fantasize about that childhood with friends she never had. Her being a princess I think has only made her more ripe for AB/DL, as the pressures of being a leader and a teacher no doubt put even more stress on her. She'd make a good caretaker too, and there don't seem to be a lot of fics exploring that possibility, but I think that's because Twilight's behavior clearly indicates a pony that often needs to chill.

1. Pinkie Pie: The rest of this list may be up for debate, but I doubt anyone could really object to Pinkie Pie being number one. In many ways, she already is what AB/DLs want to feel and experience, she's an adult for sure but she still often has a childlike innocence when it comes to how she view the world. And because of how childlike she acts (though not overly childish), I can see her easily getting into it, on her own terms, and she would definitely be an AB. Heck, some people have interpreted Pinkie's upbringing on the rock farm to imply that she never had a normal foalhood, that she may have even been without diapers or pacifiers. While the one time she was seen in diapers in the show she clearly wasn't thrilled, I think that's because she was trying to be responsible and a figure of authority, and the diapers undermined that. If she were allowed to leave her responsibilties behind for a while, but be assured that she could still retain however much control she wanted, I could very easily see Pinkie Pie willing to be padded. Though I would still imagine her to be concerned about what her friends might think of such a thing, and try to keep it secret from them.

Well, there you have it. Feel free to debate and discuss your interpretations and rankings.

5955356 I wonder which of the CMC would be most likely to enjoy ABDL?

5955356 I can't find anything to argue about on this list, it's pretty spot on. :)

5955528 There's already a list for that.