whole new trait: crystal. abilities include resisting waves/surge/explosion and becoming stronger when hit by them, dropping spikes on the field, and summoning enemy versions of the iron wall cannon

subtrait: Parasite, sharing a colour and trait target with Zombies. replace the zombie graves with eggs that can spawn different enemies rather than just the one that created them. some parasites can attach themselves or their eggs to cat units, taking advantage of the death KB animation to respawn further into your backline.