[1.2.1] Untargetable enemy that does nothing

[DOZO]

I fought an elite alchemist vampire from a grave in the Old Forest who was able to have several golems at once for some reason. After dying he left one of his golems behind, but it does nothing, has 'unknown' HP and can't be targeted (try it and see what happens.)

Here is my save: https://mega.co.nz/#!ENBRzL6a!vbfzCtfbN ... OfrDOT3CTM
It's a 1.2.0 save converted to 1.2.1, but I had not entered the Old Forest yet when I converted it.

Additionally I seem to be able to dig up the same grave multiple times, should that be possible?