Modified to produce heavy but viciously sharp spiked balls instead of regular spikes. Do extra damage to Ceramic Bloons.
~ BTD5 Official Description
Produces spiked balls that do extra damage to Ceramic and Fortified bloons.
~ BTD6 Official Description
Spiked Ball Factory is the third upgrade for Path 1 of the Spike Factory in Bloons Tower Defense 5, costing $2040 on Easy, $2400 on Medium $2590 on Hard and $2880 on Impoppable. It makes the Spike Factory produce spiked balls that pop 16 bloons (20 on Mobile) each and do three times the damage to Ceramic Bloons. The spiked balls are black balls with orange spikes coming from them. Upon upgrade, a slight range increase occurs (BTD5 only). Usage in great numbers will destroy small numbers of MOAB-class bloons, but is not reliable in late game. If many are used, be prepared for a large amount of lag.
In BTD6, this upgrade makes a return as the third upgrade of Path 1 for the Spike Factory as Spiked Balls. It also pops 16 bloons per ball, but it now deals +3 damage to Ceramics and +1 damage to all Fortified Bloons, including MOAB-class with the Fortified property. It costs $2200 on Medium.