Heavy Metal Noise! :: Nickelodeon's TMNT Metalhead Action Figure
Metalhead's 'weapon' is a simple flame/missile that you place within a hole in his right hand and 'flick' from the back of his elbow to send it flying. This action feature limits Metalhead's right arm to a perpetual 90 degree bend but it doesn't encumber his aesthetic too much when the missile is removed. And since he's a robot, a limited range of motion is acceptable.
His elbows do not have any articulation, but I'm ok with that. The only issue I have with his arms is that his bent arm and his straight arm are the same length - were he to extend his right arm it would become longer than his left! If I had to guess why, I would say Metalhead's initial design probably called for some sort of action feature or interchangeable hands/weapons on his straight arm, and that feature was cut for costs. Leaving Metalhead with mis-matched arm lengths. Honestly it's not really that noticeable, but I noticed it and it bugs me just a little bit.
That said: Metalhead is so cool I recommend him regardless of any dumb old stumpy arm!
As for scale, Metalhead is a tad smaller than the Turtles, which is in line with his animated appearance.