Funny tags

Although I am the boss of my Spider Figs.

Seems to look more like a mismold to me.

Looks like there wasn't enough plastic injected into the mold.

I usually greatly admire LEGO on a lot of fronts, but I really don't know why they bothered making more than one or two molds of Visorak.

Looks a bit too even for a mismold, or even a failed injection. I'm going for either a modification or a rare mold.

Under close inspection, the edges look way too smooth to be cut. Also, there's definitely a visible difference in opacity and the weird one doesn't glow as brightly as the others. Also, it is the slightest bit mismatched. So yeah I'm thinking it was either at the beginning or end of the molding run and the plastic didn't get to the ends of the jaws.

Also i like that they have six minifig molds. They're big enough that the differences can be seen.

The Glow-in-the-Dark color LEGO uses changed between 2005 and 2006 from Phosphorescent White (classic glow-in-the-dark) to Phosphorescent Green (which is more transparent, at least in certain materials and surface finishes). People have found examples of the Tower of Toa set that come with Warm Gold rather than Sand Yellow Metallic Kanohi Kraahkan, so it's equally possible that there are BIONICLE playsets that use Phosphorescent Green rather than Phosphorescent White for mini-vissies.

As for the shape, though, I'm guessing it's a mismold. It seems perfectly plausible since the plastic seems to be filled in evenly up until it reaches a certain point on the mandibles. I'm not sure where the injection points are on a mini-vissie, but I can certainly imagine a mold for some reason filling incorrectly and ending up with this result.