A zombie? I need to get into skitters den :)

Check this topic for info: Aclinical - Hospital Smells Group [ Grand Opening ]

I did but I didnt see anything about being able to access the den... Sorry I did read through it all but it was about the vials....

Once you reach Stage 3 of progression after drinking one of the vials, you should be able to access the Zombie Den. It was announced on the news just recently.

You drink from a vial, your strain then slowly progresses (see images in said topic) and as soon as you've reached stage 3 you should be able to access the Den.