Metal Gear - David Hayter on twitter

Thats looks more like a Moa than a Gekko

Haven't played it in ages, but didn't the classic Metal Gear 2: Solid Snake (MSX/Phone) plot had, even if as a discarded plot point, the idea that there would be smaller Metal Gear-like things to act in regular combat?

Checking wiki… yep, seems like it. Plans were to make in Zanzibar 21 units of Metal Gear D (the titular Metal Gear boss in this game), and an untold number of the smaller-scale Metal Gear G, "Gustav".