I just used a box of WHFB Zombies and used a little bit of green stuff to add some 'Plague Rot' to them. Not much, just a little as I thought the detail of the Zombies themselves woud be good enough. I modelled them to look like they were shambling and reaching out for their prey, what I take as a classic Zombie pose (I am a fan of Zombie movies, go figure). Simple and I really like the way they came out. Only question is how to paint them. I think I am going to paint their flesh the same 'dry death husk' look that I use on my Plaguebearers.
I also got my third Rhino built and I used some green stuff on this one to make it look 'Nurgly'. Something I have not done on the first two Rhinos yet. I am not sure where I should go from here. It could be done, or does it need more Chaos bits on it? I am planning to make it dirty and rusted when I paint it, so that may be enough. Tough to decide.