If you know me, I'm a sucker for rats generally! With that said, rat preds are always gonna be a strong contender! I dunno why, just generally find rats, or rodents in general overall to be appealing! So mice, opossums and the like are pretty easy go-to preds for me!

With that said, I'd typically go on a pred-by-pred basis, because pokemon and digimon both have their fair share of monsters that can be great as preds and then those among my friends that are into vore can easily sway me even if their character isn't of my favourite species because it's more about them and their characters.

There's very few species out there that doesn't appeal to me, and even then, kudos to those in which they make those species I don't normally take to more appealing, because I'm not saying it's impossible! But otherwise, almost any species is fair game, heck as a furry, I'm a sucker for humans too, so if you have a human character, chances are you're gonna win with me easily.

TL;DR, I love rats as preds, rodents more generally because mice and opossums can easily fit that space for me too, but otherwise I'm open to most species as preds anyway.

By OCs, we are talking people that have their own fursonas right, and not canon characters?
A lot of my friends are easily folks I could crush on if I'm honest! Especially if we're talking generally, knowing it's not specifically a vore or paw/feet related question.

My boyfriend's OC Phyre gets an obvious mention, but is also my cheating option haha.
Among other friends though, Mukiro is the first that came to mind, easily a crush, both somali cat and human forms!
RaccoonVandal's Ruka and Kozu are easy picks too that I swoon for!
LowenMothbat's Rowan, Kohen and Forest are my faves (though Lowen has so many to choose from!!)
Fish and Deocks have themselves too, I'm surprised we haven't done more together with the three of us!
Ipipo and Labbeh not only being good friends are also big oc crushes of mine, not to mention the plethora of characters both guys have additionally to their mains!
FeetyMcFoot's Leo is an easy crush, also as is MegaSonic's King Anthony and Apollo~
Given they're my pets, I'd be terrible to not mention Crash and Daxon too x3
I have many more friends with many crushable OCs but these are among some that came to mind for right now.

Well WereLeaf and Mobian Leaf are essentially the same person (unless ya meant Anthro Leaf, different style and continuity.) Assuming Leaf's werefox form was a separate entity from Mobian Leaf (maybe cloned, who knows) in terms of statistics, Leafvee doesn't stand a chance and will be stomached easily. Mobian Leaf has a lil more mobility than WereLeaf, but his Werefox form has more strength and probably to some extent more durability.

In short, regardless of who samples whose soles, WereLeaf will devour them both easily and can sample their soles during the swallow. The only way Leafvee is sampling soles is while he's pinned underfoot by either predator, and if it works out differently, Mobian Leaf might get to sample Leafvee's while consuming Leafvee, but not long after will he get eaten by his lycanthropic counterpart. Not saying it's impossible for Leaf's fox form to devour his werefox form, but honestly, I'd say it's a flat d20 roll with a high DC to meet. Basically, the odds aren't in favor of fox Leaf getting the upper hand on werefox Leaf.

So actual Werefox Leaf will come out on top either way, to face the mysterious CHALLENGER because I think a champion was found between the competitors here already.

Don't think for years this hasn't crossed my mind, besides paws in maws of course. I've always wondered how the concept of "paw vore" would work and it never sat quite right with me in a way that made me say "this works, I can roll with it."

Closest to it is like absorption, whether physical or goo, and it's like the closest to it working.

With that said, I've seen a paw with a maw on it before, a couple of friends played with this idea and I'm not gonna lie, it's pretty cute and has me curious. If it was something I saw more, maybe I'd be interested? I know someone else that played with that concept with mouths manifesting on feet more particularly, but their character was also a human-shaped tentacle monster, so it had a lot more than that going for it xD

But yeah, I'm curious enough to see if that kinda thing would interest me to play with such an odd concept!

This is a tough one. If we're talking generally, it's easier for me to think of users than canon so... Cerin would be my rival, though it's a friendly positive rivalry, not a bad one. Other allies would just be other friends and the like. My boyfriend Phyre would be a great ally, as would Muki and Dewwy among many others.

I could probably speak better from a story perspective in regards on Mobian Leaf in a Sonic AU world, since I kinda have that canon going on, in which I accidentally tie him up with Shadow to a degree which at best can make them allies, or at worst affiliated. Still working that part of the story out. In more general/relative terms, I guess Leaf would rival Knuckles as a fighter, I tend to make Leaf pretty strong but not fast that he might be able to give Knuckles a run for his money in a fight, but while I had considered them crossing paths, there was never a necessary need for them to fight.

Story wise, the only canon rival I had was technically in a negative sense with Infinite, as I have a story idea in my head which runs parallel to Sonic Forces but as a B side of what things we don't see from either Sonic's perspectives or that or the Avatar. No major heroics until the very end, but while Infinite deals with Sonic independently, he has run-ins with Leaf and his crew Team Spectre multiple times and ends up cursing him with a virtual power that he suffers with for a couple years. In a post-Forces world, Leaf generally stays away from the resistance due to a grudge with them blowing up the Death Egg which still housed many captured mobians, those that Leaf and crew managed to save prior to the orb's detonation. I dunno about if there's any canon allies he becomes comfortable with worth mentioning, as the AU kinda focuses more on my own characters I made for that world, along with a city built on the ashes of old.

I still need to iron all that out, so if you want to know more, feel free to ask, but know while I have the ideas, I don't have anything written down so it's very spotty what I'm trying to bring together.