Zootopia Wiki
Zootopia Wiki

The Night howler serum, also known as the savage serum, is a highly potent chemical drug made from toxic flowers called Night howlers in Zootopia. It was created by the sheep scientist Doug Ramses for the purpose of using it on predator mammals.


Like the natural flowers it is made from, this drug is capable of inflicting highly potent psychological effects on mammals. When exposed to mammals, the serum causes a chemical reaction in the brain that decreases activity in most parts except the cerebellum, which becomes hyper-stimulated, causing the victim to lose higher reasoning functions and lash out at anything that moves. The effect of this Night howler sickness is that essentially, any mammal reverts to an aggressive, wild, violent state that is described as "Savage".

Role in the Film

Doug making serum pellets

Under the orders of his client, Assistant Mayor Bellwether, Doug goes around purchasing Night howler flowers from Duke Weaselton and sets up a small farm of them in his makeshift laboratory in a subway. Once they are fully-grown, he converts them into a serum using a vat and a chemistry set. The serum is then placed within small glass paintball-like pellets and loaded into an air-powered sniper gun, which is used by Doug to dart dozens of predator mammals for Bellwether's plot in order to make prey animals fear the predators.

Nick with the case of evidence

Judy Hopps and Nick Wilde discover the serum in Doug's lab and they later learn that Bellwether is behind the conspiracy.

The farm of Night howlers in Doug's lab that are used to create the serum is destroyed when the lab is accidentally derailed by Judy and Nick and subsequently explodes. After finding out that Bellwether is the mastermind behind the conspiracy, Judy and Nick make a run for it, but they are trapped in the Natural History Museum by her and her henchmen. Bellwether shoots Nick with the serum to make him go savage and kill Judy, but it turns out that they switched the serum with blueberries and recorded her plot with Judy's carrot pen. After Bellwether's arrest, a cure for the serum is developed for the affected predators.


Zootopia Wiki has a collection of images and media related to Night howler serum which can be found at
Night howler serum/Gallery.

v - e - dObjects
BlueberriesBogberriesCarrotsDonutsJumbo-popPawpsiclesSunflower Soda
Doug's labFinnick's vanHopps Family Farm truckJudy's meter maid cartJudy and Nick's police carRainforest District gondolasZootopia Express
Carrot penFox repellentMuzzleNight howler dart gunNight howler serumTame collarTranquilizer gun
Dancing with GazelleEucalyptus caffeine pillsJeweled acornNight howlersZootopia Police badgeZootopia Transit Authority