I had this idea when I was messing around with player heads. I decided to make a mob with similar properties to the player head, in the sense that it takes on the skin of the given player.
Feel free to use this mod in a mod pack; I won't be updating it any more, however, because I lost the source code.
Now adds a way to craft spawn eggs!
That's right! Craftable spawn eggs! Now you can spawn Humans (among other mobs) in survival!
Just craft a blank spawn egg, like so:
After you craft it, you can either right-click a mob, and get that mob's spawn egg, or you can click anywhere else to get a Human spawn egg.
You can name them like you would any other mob, and that name will determine what player they look like.
You can befriend them by throwing a diamond at them. This also gives you the "Diamonds to you!" achievement, if you are at the appropriate progress level.
They will attack hostile mobs if holding a sword, and shoot them if they have a bow. They also attack if you haven't befriended them yet, regardless of the weapon. (You can't see it, but Notch is holding a diamond sword.)
Got a suggestion? I'm all ears. Post any suggestions (yes, any) in the comments below. Maybe certain names drop certain objects? Maybe certain names make changes to the AI? Whatever your suggestion is, don't hesitate to post. Nothing (and I mean nothing) is too ridiculous.