Bonnie is a hardworking Bloonstone miner who constantly throws around sticks of dynamites that act like spikes, popping any Bloon they come to contact with. On Level 2+, Bloonstone minecarts will start spawning and moving along with natural Bloons. They will drop Bloonstone that grant cash on destruction, and their reward can be increased or reset on Bonnie's menu, but upgrading them so will also increase minecart's health. Lives are not lost if minecarts leak.
-Description (a. to Bloons Wiki)