Gaiaterra: Elysea's Conflict/Guardian Drone

The Guardian Drone is an Aquilan drone armed with a 40mm cannon to engage vehicles

Short story
"Back in the Army, we always had two major rules that we were to follow at all times. First: Do not -ever- leave your fellow Marine behind in a fight. Second: If you can't drop an enemy dead with your gun - use MORE gun! The second rule must have been one of the few things that the R&D eggheads have actually learned from our previous engagement with Voshkod and the MLA, so they created this little guy right here: The Guardian Drone. This amazing box o' fun on treads is basically a remote controlled mini tank - I bet you would have loved to find one of these under the tree on Christmas. Armed with a short 40mm cannon, the Guardian packs enough punch to blast holes through light vehicles and it is both small and agile enough to support our grunts in close quarters. Its treads are built to be very sturdy to compensate for the recoil of the weapon, which also allows the drone to bury itself into a hull-down position for added protection. The Guardian stands as a fine example of our new doctrine: First you send in the robots to secure a foothold and then you get boots on the ground to seal the deal. Rumour has it that the Alliance are currently developing a new type of light tank for the exact same purpose. I hate to break it to the guys in Aselia, but... manned tankettes have been out of fashion since Voshkod-Aquilan War. I guess they missed the memo."