Universal moves:

Jab: Standing low punch
Forward tilt: Standing low kick
Forward tilt angled upwards: Standing high kick
Forward tilt downwards: Crouched high kick
Down tilt: Crouched low kick
Up tilt: Standing high punch
Dash attack: Sub-Zero's slide. Yes, both of them have it.
Forward Smash: Roundhouse (Backwards high kick)
Down Smash: Sweep (Backwards low kick)
Up Smash: Uppercut (Crouched high punch)
Neutral air: Jump punch
Forward air: Forwards jump kick
Up air: Upwards jump kick
Back/Down air: Ones based on Ryu/Terry's since classic MK doesn't really have moves suitable for them
Pummel: Close kick
Forward throw: Unmasked Sub-Zero's throw, with an extra spin due to the victim being thrown forwards
Back throw: The palette-swap ninjas' usual throw in MK1-3
Up throw: Close high punch
Down throw: Scorpion/Sub-Zero's throw in MK4
Side B: Dial-A-Kombo: Similar to Marth and co.'s Side B but with moves Scorpion/Sub-Zero use in their Kombos in UMK3. Animations are different depending on who's used.

Scorpion specials:
Neutral B/QCB+A: Demon Fire: Comes out a little in front of him unless the FG input version is used, which will actually try to target an opponent.
Down B/QCF+A: Teleport Punch: Works more like Greninja's Shadow Sneak in order to work in Smash's environment. FG Input version deals more damage/knockback.
Up B/Back+Back+A: Spear: Grounded version works like it does in classic MK, FG input version is slower but tries to aim where the opponent is on the ground, and meteor smashes if it hits in the air. Aerial version aims the spear upwards in the air unless you quickly tap forward, and is used as a tether recovery.
Final Smash: Welcome to the Netherrealm: His super from Injustice 1.

Sub-Zero specials:
Neutral B/QCF+A: Freeze: Contrary to its name, you'll actually have to barrage an opponent with multiple Freezes to get it to actually freeze. 4 for the Smash input version, 2 for the FG input version.
Down B/QCB+A: Ground Freeze: Smash input version works like it did in MK, making the victim slide backwards. FG input version makes the opponent trip, as in the infamous Brawl mechanic.
Up B/Back+Forward+A: Ice Klone: Can work as a shield or a platform you can jump on to reset your jumps, but you can't make another Klone until you're back on the ground again. FG input version blows up upon making contact with an opponent, freezing them.
Final Smash: Deep Freeze: His super from Injustice 2, except it stops after the hammer.