Sharpsville, PA
That's not quite correct. The part you've circled in red is attached to his arms, and I believe it is a counterweight for the monster's arms. It balances the arms so that they swing up and down when hit, and lower when he is laying down. The manual calls it the "actuator arm"
Here is a screenshot of page 2-27 from the manual. I've circled two parts in red. One is the arm that limits how far the monster can lean forward, and the other is the slot that this arm fits in. I had luck preventing the monster from leaning too far forward by bending that arm to an angle less than 90 degrees.
