You didn’t think I’d forgotten about the “Take Back the Pit” contest starting today, did you?  Of course not.  The first installment, and the first clue is below!
Dr. Venom still remembered the dubious look he got from Cobra Commander when he made his return.  Certainly he didn’t expect a genetic mastermind like Venom to be so easily destroyed?  Sure, it has been over two decades, but these things take time.
The Commander had looked even more dubious when Venom told him his plan.  Yet, he still donated a trio of Python Patrol Stuns and the use of a squad of one of his most unique troopers that would prove useful to this Cobra agent.
Slipping over the desert sands, Venom remembered what the last location of the G.I. Joe Mobile Command Center had been in the Utah desert.  Could he hope G.I. Joe still had a presence there?  Cobra intelligence had said that G.I. Joe was possibly testing a new mobile headquarters in this region of desert…a state of the art mobile version of their underground bunker, The Pit.  He wasn’t convinced, but he made the trip anyway.  Turns out Cobra Intelligence had improved in the last twenty-five years…looming before them was the mammoth slant-armored behemoth that he instantly recognized from the stolen documentation…he had found The Pit.
He and these Cobra Troopers silently disembarked from the stealth cloaked vehicles and moved towards the mobile base as it rested atop four trios of monstrous rubber tires.  Security was slim…after all, this was just a test run, and nobody was supposed to know, right?
Venom gathered together his mysterious Cobra squad…

CLUE #1

Like the Mass Device Element, they’re not light.
But you see them best when it’s not bright.
Who are these Cobra Troopers, and what does General Hawk think of them?