On wave 5 there are 2 bosses ( on hard mode 4) that drop metal plates, on wave 10 there is Super Rocket Toilets that drops Batteries. On Wave 15  there are 2 Hydra Strider Toilet ( on hard mode 4) , wave 20 spawn Blade toilets , they dont drop anything. Wave 25 and there are Dual Buzzsaw Toilets that drop buzzsaw item with 10% chance, wave 30 spawn Flying Cargo Toilets, if you defeat them , then good luck! Because after defeating , containers drop more strong enemies that can stun your team! Wave 35 , The Scientist Toilet, he dont drop anything.

So you made that far... Now you need to defeat Infected Titan Speaker guy to win! every 10 second he stuns alliance for some sec, actually the boss is so slow but has a lot HP. As Reward of beating raid is Raid key wich you can use in raid crate, also there is a chance to get Titan's Speaker (2.5%) or Upgraded Blaster (2.5-3.5%)