Question concerning undead

[Doresain]

What would be the most balancing way to create a zombie with the unkillable variant in game? (or better yet creating any of the variant mindless undead)

LM doesnt go into actually creating them, other than an incread CR and its new abilities

[KillianHawkeye]

I would allow a PC wanting to create a variant undead to make a Knowledge (religion) check to know the appropriate details. The DC would probably be moderate to high difficulty depending on how powerful the variant is (maybe figure something out based on the CR increase?), and then the creation would proceed as normal.

Alternatively, you could require some rare material component (in addition to what is normally required) to create a particular variant.

Or just let them do it as easily as normal undeads. Of course, it's all up to the DM to figure out what would be reasonable in his/her game.

[Doresain]

how does this sound...for the purposes of creation, the undead is treated as the lowest possible HD for the target CR...

example: lets apply all of the variants(hunting, diseased, fast, unkillable and bloodthirsty) to a standard human commoner zombie, this would increase its total CR from a 1/2 to 4...the minimum HD for that CR is 12, so as long as you meet the CL requirement to create it (which i think would be a CL 6) and use an onyx gem worth 300 gp, you would be able to create a 2 HD undead that has a bunch of nifty little abilities...

thoughts?