Why in the Nine Hells is this a Humanoid? Gargoyles are either Magical Beasts or Monstrous Humanoids. Which makes this creature the single best choice as a form for something like an Ogre Mage, a Slaad or a Rakshasa. The picture is nice, I imagine it's from the 1E Tomb of Horrors and reproduced in the 3E version?

Obviously -0, of course. The monster itself is a as bland mechanically as its encounter design is. And yes, we're talking "when the PCs enter the room, the gargoyle in suspended animation in the middle animates and attacks them. It has a collar of gems to reward them for the fight.".