This exact thing happened to me today. I was knocked into lava by a zombie, then I came back to recover some of my gear and found I couldn't hit it with my sword, and it actually killed me again (although this time it just ate my brains). I can't positively say it was the same zombie, though. Pokechu22's assertion that "they don't actually exist" is false... or he could be reporting a different issue.
Edit: I should add that the second time, when I was fighting the zombie I was cornered in a narrow 1x2 recess in a wall. There's basically no way the zombie could have just been in a different place than it appeared on my screen, or else it wouldn't have been able to hit me, so I don't think it is just a graphical issue.
Garth Bowden
This exact thing happened to me today. I was knocked into lava by a zombie, then I came back to recover some of my gear and found I couldn't hit it with my sword, and it actually killed me again (although this time it just ate my brains). I can't positively say it was the same zombie, though. Pokechu22's assertion that "they don't actually exist" is false... or he could be reporting a different issue.
Edit: I should add that the second time, when I was fighting the zombie I was cornered in a narrow 1x2 recess in a wall. There's basically no way the zombie could have just been in a different place than it appeared on my screen, or else it wouldn't have been able to hit me, so I don't think it is just a graphical issue.