While I don't really have any mechanical complaints about this class, the thematics drive me up a wall. This stems largely from the differences between the race and the monster. A standard zombie has immunity to poison (damage and condition) and the Undead Fortitude feature. More than anything, that's the core identity of the Zombie. 

They both have Darkvision at least. The monster is slower, but we can easily write that off as being an intelligence thing. Your zombie has poisoned immunity, but not poison immunity. Yuan-Ti have it, so it's not like there's no precedent. While That's a big part of the Yuan-Ti's power, Zombies don't otherwise have much going on. Zombification implies your creature type changed to undead, but doesn't actually state it. That's really important to resolve one way or the other.

The other big element is Undead Fortitude which is completely absent from the race. This is surprising since the Half-Orc's Relentless Endurance is a pretty easy match. In fact, the half orc would have been a pretty good place to start designing this race. Flip the ability mods and drop Savage attacks and you're almost there. That'd also explain why you gave the zombie Intimidation proficiency (while still being a mismatch against the monster), though the stealth proficiency still makes no sense.

My recommendation would be: Drop both skill proficiencies from zombification and raise the damage resistance to an immunity. Explicitly state if the creature type is Humanoid or Undead. Drop Zombie Scratch and add Relentless Endurance.

I've been working on a better version (specifically to address if it classifies as undead regarding healing spells), mostly just conferring with friends if it being undead would ruin the race or if them being able to heal would make it too much.

I was unaware of the poison damage immunity on Yuan-Ti, and assumed full immunity to a damage type would be too much. I am afraid most of the issues stem from my own dislike of making something that seems "too op"...

Also, the stealth proficiency was because I was batting around the idea that the race would eat the flesh of the living/recently dead, and that would require some level of being able to stay hidden while feeding...

I'll definitely take these into consideration while working on a new version, thanks.

Hi! I really like this concept, however, I feel that it is lacking. Just as Vaegrim said, this race would benefit from a trait similar to Relentless Endurance. I would also like to question why you didn't give this race a feature to negate turn undead or similar spells. Another point Vaegrim had that I agree with is dropping the skill proficiency of stealth at least. A tiny change that I feel would help is making the damage from Zombie Scratch necrotic instead of slashing as it more thematically fits the zombie.

I am unaware of any feature that would negate a turn undead spell or anything like that, if you have an example I would love a link to it, my current testing version is using something similar to Centaur/Minotaur's Hybrid Nature feature to give it a Humanoid/Undead listing.

Unfortunately I'm unable to change the natural weapon damage to special damage types, only slashing/piercing/bludgeoning, so that is something you'd have to take up with the people who run DnDB, not me.

You call it an Intelligent Zombie, but there is not one INT modifier? What makes it intelligent, and not just a regular zombie?

...The fact it would be a playable character.