User blog comment:GameboyGabriel/What new things will there be in BTD6?/@comment-9268528-20130608043308

plastic-takes a lot of hits for sharp objects but not so much for explosive and fire to destroy

iron-like lead and ceramic and zebra altogether but can rust with water tower and if it does, it will turn into a ceramic. Also turns into ceramic when destroyed.

Water tower:

Sprays water at bloons to slow them down. Upgrades to poison hose.