The Loot-o-Tron 5000 is unlocked in the Chaos Laboratory, and is created in the Chaos Factory. The best way to use it is to wait until all towers are down and then use it. Do not use it in the range of ADT towers as it is considered a flying monster and will be blown to pieces if an ADT is nearby. THIS IS NOT USABLE ON OUTPOSTS! IT IS ONLY FOR TOWN HALLS! Also High leveled Teslas can easily take on a low leveled Loot-o-Tron 5000 in less than 1 shot (considering that there is more than 1 high leveled Tesla).
The Loot-o-tron is also good when used against the Kozu tribe, as you can get a huge amount of resources fairly quickly.