The Mars Gigantalos is a massive single-pilot operated Tank developed by the Professor during his time in the Rebel Army, but was made reality when he joined the Martians. It first made its debut on the game's event titled 'Try Line 3rd', where it was also a playable unit.
"The Professor designed it while he was with the Rebel Army, but this mysterious robot could not have been completed with Earth technology alone. It was finally completed on the distant planet of Mars. Based on the telepathic capabilities of Mars People, pilots sync consciousness with the robot to control the unit. It switches to its second form after taking a certain amount of damage, but it shakes a lot and is liable to make pilots nauseous (according to the Professor)."
- ~Metal Slug Attack in-game description.
In Metal Slug Attack's event, the Mars Gigantalos was the featured unit of Try Line 3rd's Campaign Box Crank. It is a massive contraption created by the Professor, and it slowly moved towards the enemy. Enemies in range would be either met with by energy saws, and those who were too close were met with energy pulses. The Professor was also capable of moving the Gigantalos to the front lines, where it would deploy its Gigan Arc Energy to stun enemies in range, and would also regenerate itself in the process.
Attacks that would have caused the Gigantalos to be stunned would prompt the Professor to activate its' countersystem, where it would absorb the incoming stun attacks and make itself briefly invulnerable, deleting incoming projectiles that struck it in the process. If the first form was destroyed, the Professor would detach the "head" from the body, before moving around and firing beam rings at enemies below him, and could not be attacked by enemies. After a set amount of time, he would slowly drift upwards and leave.
|Mars Gigantalos - The very first and original version, piloted by the Professor.|
|Christmas Gigantalos - A fairly incomplete Gigantalos version, with the head having been created. It is piloted by Percier and can also fire a beam ring like the original version, but was also modified to move faster and contains a hatch to drop poison bottles from above.|
|Golden Gigantalos - An upgraded version of the predecessor which is painted gold and piloted by Marty. It's weapons have been enhanced. Marty piloting the Gigantalos has given it improved synchronicity, and as a result it is capable of restoring its body when it has remained in its second form for some time.|
|Mars Percier - A pink version of the Mars Gigantalos, piloted by Percier. The attacks are similar to the original, except when the body is destroyed, Percier hovers around the battlefield dropping poison bottles on enemies.|