Zombie Skills/Scent Trail
From The Urban Dead Wiki
Scent Trail is a zombie skill which allows the zombie to "track" an attacker. It only works when the zombie logs in and if a person has failed to kill them. It will also work if a person uses a DNA Extractor on them, uses a First Aid Kit on them, or tries to revive them (In case of Brain Rot).
The ability will not work if the zombie is killed, successfully revived, or the person attempting to do any of those things is killed. It will also go away if the survivor responsible travels far away (10 blocks).