The Zombie Syringe can be used to instantly grow baby animals or Villagers into adults, in the same way Growth Hormone Syringes do.
It can be used either by hand, using right click, or with the Veterinary Station. When powered, the Veterinary Station automatically use a Syringe on any baby animals within a 5x5 block area in front of it, using up a Zombie Syringe every time an animal is injected. Empty Syringes are returned after use.
When used by hand, the Zombie Syringe will turn into an Empty Syringe, and can be refilled, to use again.
Unlike its counterpart, the Growth Hormone Syringe, the Zombie Syringe has a downside. It will occasionally turn the baby animal into a grown Zombie, however this is a rare occurrence.