Yes, definately yes.

I'm the friend antonok was talking about.

Before I go on, the undead everyone was talking about is the Necrosis Carnex. It has a 1d6 +1 per 2 HD negative energy touch that heals undead. While they dont have a damaging aura effect like these guys do, living creatures within 30ft take a -2 to attacks and saves. Their explosion only does the same amount of damage as their touch in a 30ft radius spread. They're medium and 4 HD and require a CL of 11, specially prepared cold-hammered iron bands costing 200gp, and 3 corpses from medium creatures to make, using the Animate dead spell.

Stat-wise, the carnex and the diminutive heart are a close approximation of each other, so that's cool. They seem to be balanced as well based on their HD at higher levels too. Carnex has a CL limit, but I guess that's the price for having an Int score. Overall, I like these. I think the Size needs to be bumped up a little, as mentioned. Human hearts are about the size of a fist, which strikes me as diminutive, 3 sizes smaller instead of 4.

I've skimmed over some of the other entries in this series in the past, but havent given them a thorough read yet. A lot of them seemed... well, a little silly, to be honest. But this particular one, I like. The rolling eyeball and empty skin look promising too, I'll have a look and get back to you on those as well.