Sub Zero
Now on to Sub Zero. I have limited match up experience with Sub, so some of this will be theorycraft, THTB, if you could help a bit more on this one I'd very much appreciate it, but, I did play against one at the last tourney I went to, and as long as you don't give him a chance to control the level with clones, as in, not letting him get distance, and getting right on his tail, I feel a lot more comfortable about it.
When it comes to Sub, especially since such a offensive and rushdown character such as Reptile, he is going to try as hard as he possibly can to keep that starting match distance between you two. Setting up a grounded ice clone greatly hinders our approach, and makes his zoning a ton more safe, considering we cant rush in. For SF players, it's basically a Guile set up, just safer. If we jump in, he'll AA us, if we rush in, in this case, we get frozen, if we let him zone, it lets him build meter, albeit slower in MK then in SF. Our goal is to close that distance, any way possible. In this particular match up, it wouldn't hurt to build your meter for X Ray, to tag him on baited out ice clones, from what I hear, it goes through ice clones? (I'll test this tomorrow before work.) From what I've noticed, Sub doesn't jump in a whole lot, so we don't really have to using meter to tag him with ex FB and ex green hand, if for whatever reason he does jump in, just use standing 4 (I think it's standing 4, if not, forward 4? The windmill kick thing Reptile does.) and conserve that meter for the ninja x ray.
Tools he has against us:
Ice Clones: The bane of our ground approach whatsoever. This tool, combined with ice balls, makes it fairly difficult for Reptile to get close. Most of the time, a clean freeze allows Sub a full combo, albeit smaller since he only gets one freeze a combo, normal strings aside. You need to do everything in your power to avoid letting him set up these clones, whether it be zoning to get a clone to dissipate, doing significantly less elbow mix ups while he is grounded, being careful on counter attacks while he is sticking you in place with block strings, and being super careful on your jump ins. This tool can easily make or break the match up for us, just like us, once Sub gets rolling, it's difficult to stop the force.
Ice Ball: While not as scary as ice clones, Ice Balls are still a threat in their own, whether it be zoning, in combos, or paired together with an ice clone somewhere on screen. Sub can make each level of the course difficult to get close to him by, setting up an ice clone in the air and zoning with ice balls while grounded makes Sub a tricky character to catch up to. Especially keep an eye out for Ice Beam, since it's full screen, a Sub might bait out an approach with zoned ice balls, throw out an ice beam, and catch you, just keep your eye out. Most the time, like I stated earlier, on a clean freeze, he has enough time to get a full combo off, from most distances of the screen. (Not sure if freeze lasts long enough to get a combo off from full screen?)
Ice Puddle: Considering Reptile has multiple options out of the corner, and this move shines in the corner on resets, not one of Sub's stronger tools, albeit still useful for resets in general. Purposely whiffing a normal string to end the combo in this can end up in another full combo, so just keep an eye on it, and be ready to jump. Generally pretty easy to read and react accordingly though.
Slide: Just the generic slide special. Easy to block on reaction, full combo on block, general same use as the other slides, to tag someone on a low, but, if you know they won't react quick enough, just easier to get them with Ice Puddle. This shouldn't serve a problem whatsoever in this match up.
How I approach the match up:
First thing is first, I almost always start the match with an elbow dash or a forceball. Pressure is a good start, having something on the screen, or someone advancing towards them just gives them another thing to have to worry about, giving you a bit of more time to react. Once Sub starts trying to get his ice clone silliness going, thats when things have to get significantly more careful. Usually, the second the ice clone goes down, assuming he isn't throwing an ice ball, I do elbow dash again, or ex, just to try to close some more distance, and potentially get a jump in. Assuming you don't have enough time to jump in on him, just be ready to zone if need be, acid spit is an amazing tool. If for whatever reason he starts trying to approach you, the match up should be in your hands, just try to not let you two be too far apart from each other, and if you do get seperated, try to have a forceball going, hard for Sub to punish full screen besides ice ball.
Tools we have against him:
Acid Spit: Our zoning tool against Sub. In this scenario, a trade is less beneficial, but, it should give us enough time to get unfrozen and not get comboed. Not much else to say, don't be too crazy with it, we don't want him freezing us for whatever reason.
Elbow Dash: Gives us the ability to close distance, tag him on normal string mess ups, and ground mix ups, although we have to be significantly more careful with them, in fear of him wake up ice cloning.
Slide: Does Slide go under ice ball? I'm sure sweep does, which isn't a bad option at close range, but Sub should only be doing Ice Balls at close range in combos. Does Slide beat out puddle, or do we still slip?
Forceball: Gives us a bit of screen control back, since if he keeps zoning he'll get tagged by a forceball, and with elbow dashes we should be able to advance and at least get a bit of damage in.
Ex invisibility: \ While not as useful as it would be in other match ups, still not a terrible option. In this I feel we should save our meter for x ray more than anything.
Green Hand: Allows you to get him away from you on a blocked 321, like anyone else, but, besides that, nothing too different. Corner combos, an occasional AA, nothing too special.
X Ray: This match up in particular, assuming X Ray does go through Ice Clones, saving your X Ray can be very important. With a full meter, one mistaken Ice Clone could cost Sub a lot of life and a positional disadvantage.
I feel Reptile players are gonna' have to put a decent amount of work in to fight against a adept Sub Zero player, due to his ability to shut down our approach. Possible to win it, but we're gonna' have to do a good amount of work. Once we get close, the match up is basically ours, but, getting to that point can be a bit tricky. Be patient, and wait for the Sub to make a mistake, and capitalize.
45:55 (I really wanted to make it 45:55 due to the fact of we wreck him pretty good when we get close, but I personally feel his ability to make it difficult for us to get close outweighs that.
+
and 
+
are both pretty good. Not to mention his AMAZING sweep.