WELL. I think I have a small theory (if even THAT) about who (or what) they are. Think about it. White eyes. One of them was holding sand. [SAND PYRAMIDS] This is a pretty big strech, but it's creative. THE NEW MOBS ARE HEROBRINE'S DARK ESSENCE. Notch deleted Herobrine. But Notch could say that 'He' somehow emerged again as shadow versions or something! [WINNING IDEA]
Well if they build you can first capture a few (you know with fences) make them build (or let them build) some safe place to stay, then kill them all. Mwhahaha, then you could have your own slaves. You know unless they from a rebellion and kill you:(
I also just went to mc wiki and it seems that more surprises are still on there way. Yes thundermuffin is right, they are called endermen, there also seems to be a few more mobs on the way. Dragons, fish, pigman (not zombie) and silverfish. Well we can only sit (or play) and wait
Wow, i hope there are more mobs. It looks like they can transform. This is going to be amazing. Is it just me, or does it feel like Notch is against us xD.
Here is a small portion copied from mc wiki for curious people on new mobs
Aside from zombie pigmen, living pigmen have been confirmed to appear in a future update.
In the Halloween update, Notch said he would add fish.[citation needed] However, he had limited time, and was thus only able to add them as an item. There is coding for fish in the game, but no model exists at this moment.
Dragons - Notch hinted during the Spider-Jockey update that he will add Dragons to the game. Dragons may also be able to fly or breathe fire. Notch confirmed on his Twitter that he will definitely add a form of flying transportation. There is a chance that Dragons may be able to be ridden in a similar manner to pigs.[3]
Notch confirmed during the Brocraft.net stream that he will be adding prefix mobs. This means that there will be mobs such as 'Burning Spider' 'Giant Zombie' 'Cobble Creeper', etc. It is not known if these are still planned to be in a future update.
A "scary monster" is planned to appear in the 1.8 update.
A new mob texture was found with Beta 1.7, titled silverfish. This mob may be one and the same with the "scary mob" mentioned above.
Jeb recently posted that he likes the idea of players deciding when to summon the boss mobs like in Terraria, which means that boss mobs may be added in 1.8.[4] Notch recently said something similar in an interview.
Notch said he was working on a new mob after drinking some coffee. This mob was shown a few days later, called an Enderman.[5]
Kerbals, kerbals, everywhere, where they stop, I don't care!Kerbal Space Program
Aside from zombie pigmen, living pigmen have been confirmed to appear in a future update.
In the Halloween update, Notch said he would add fish.[citation needed] However, he had limited time, and was thus only able to add them as an item. There is coding for fish in the game, but no model exists at this moment.
Dragons - Notch hinted during the Spider-Jockey update that he will add Dragons to the game. Dragons may also be able to fly or breathe fire. Notch confirmed on his Twitter that he will definitely add a form of flying transportation. There is a chance that Dragons may be able to be ridden in a similar manner to pigs.[3]
Notch confirmed during the Brocraft.net stream that he will be adding prefix mobs. This means that there will be mobs such as 'Burning Spider' 'Giant Zombie' 'Cobble Creeper', etc. It is not known if these are still planned to be in a future update.
A "scary monster" is planned to appear in the 1.8 update.
A new mob texture was found with Beta 1.7, titled silverfish. This mob may be one and the same with the "scary mob" mentioned above.
Jeb recently posted that he likes the idea of players deciding when to summon the boss mobs like in Terraria, which means that boss mobs may be added in 1.8.[4] Notch recently said something similar in an interview.
Notch said he was working on a new mob after drinking some coffee. This mob was shown a few days later, called an Enderman.[5]
Heres a small reference
Dragons,pigman (not zombies), fish, silverfish