A long time ago, back before running was implemented, I once saw a tank drone fighting a horde. It was at ||| by the time I found it so that must have been going on for quite a while. I’m pretty sure it saw me, but apparently the horde had higher priority because it was right next to the drone, so I had time to break the line of sight by hiding on the other side of a house before it could reduce me to ashes. I stayed there for quite a while, peeking out and watching as the horde kept reviving, doing paltry amounts of damage, dying, reviving, rinse, repeat. Eventually the tank drone was at :, so I waited until the horde was all dead, ran the opposite way to my car, grabbed a katana, went back and let it see me, then ran inside the house and waited beyond a wall that broke line of sight with the door. I waited there as the sounds it made came closer and when I thought it was inside the house stepped out right next to it and dealt the final blow with the katana. I think it only did like 47 damage but that didn’t matter because the horde had done the rest of the work.
I know I didn’t actually kill the drone since the zeds did the lion’s share of the damage, but that’s still the coolest thing I’ve ever done on Cataclysm. That’s also when I found out that Tank Drones take 8 hours to dismantle and when I found out how difficult it is to do something for 8 hours uninterrupted.