I don't think it's fair for the tanks to fight against her, she had way too many medical applications over the years.
Butterscotch is a Boss tank what can spawn in FFA. Instead of overwhelming the tanks like a usual boss, it spawns giant drones what do massive damage.
The design is a yellow circle base with 2 drone spawners on the left and right, just as simple as that.
Butterscotch can create a maximum of 6 drones, what look more like chips than drones.
Once Butterscotch's health reaches 0, Butterscotch will split in half and then fade away. Any drones that were still alive would do the same effect.