Body and turret assembly - Cobra H.I.S.S.
Canopy and turret cover w/antenna - Yetibrew Design (Shapeways)

The H.I.S.S. is not a tank. Yes, it has tracks, carries some good firepower and is maneuverable in the battlefield. But tanks are, by definition, armoured vehicles and the H.I.S.S.'s glass canopy precludes it from meeting the definition. No vehicle on the front line of combat is going to last long if its driver can be killed with a round of .50 BMG. And the open-top turret doesn't help either, it would be too easy to lob a grenade into it. Hasbro never called it a tank, of course, that's something that fans added themselves.

To make the H.I.S.S. into an actual H.I.S.S. tank, I bought a couple of 3D-printed parts intended just for that purposes: an armoured canopy, and an armoured turret cover. I had to modify the turret cover, since its design is to replace the turret rather than cover it. So I had to cut out the front of it to fit in the turret. Reproduction stickers from Toyhax.com complete the look. I call it a H.I.S.S.-A both to reflect that it's a new model of the vehicle, and to indicate that it's armoured. The pics also feature two custom figures - the Strike Viper as the driver and a Cobra Dragoon on the back.