The Terra-tron is merged from an entire Terran base and is a very large and powerful ground unit. Specifically, one Planetary Fortress, four Supply Depots, four Bunkers, one Factory, two Barracks, one Starport, two Fusion Cores, and one Ghost Academy merge into one Terra-tron. The Terra-tron was the Starcraft 2 April Fools Day joke for 2009. Karune has suggested that the Terra-tron may be available in the map editor. The page on the Starcraft 2 website for it still exists, and includes many Transformers references.
The terran military has always been known for its superior base-defense capabilities and constant drive to improve its fortification technology. Take, for example, the newly developed Ares planetary fortress and Crucio siege tank, or the heavily upgraded Broadsword missile turret. A few of these alongside some bunkers packed with marines provide a solid wall of armor, neosteel, and firepower to repel any threat, alien or domestic.
But over the course of a prolonged defense, even the most hardened armor will crack; missiles and ammo will be depleted; and the toughest troops will be worn down. To create a truly comprehensive defense for high-priority, mineral-rich regions such as the volcanic uplands of Redstone, the terrans needed to devise an entirely new concept in battlefield strategy. Terran military engineers, led by Goraion Systems' head of development Dr. Ron Volt, have been working day and night to design a new kind of base for the terran armies: the titanic Terra-tron.
At a recent defense conference, Dr. Volt had this to say:
"With the use of magnetic flux generators and through some simple modifications to our existing building schematics, we've found we can utilize structures that already exist in our bases to assemble the frame of a siege-class combat walker—a construct that some of my colleagues insist on calling the Terra-tron. The Terra-tron is best deployed as a last-ditch effort to hold an important location on the grid. Currently the cost of operation is a bit of a problem, as energy conduits and pipes become dislodged or severed and leave dangerously exposed electrical wiring, steel framework, and sewage systems. However, let me assure you that we are working diligently on new waste-containment systems that should eliminate this problem and get our buildings back up to code in the near future."
Details on the Terra-tron's weapons are not known, but it appears that it includes the Planetary Fortress's (head) attack, a large laser that shoots out of the Ghost Academy, (right arm) and a device that looks like a laser cutter that is attached to the Starport. (left arm)
"Hell, it's morphin' time!"