Night howlers

Night Howlers are a type of flower that Bellwether and Doug use to concoct a drug that they use to turn predator animals savage, including Manchas and Mr. Otterton.

Description
The Night Howlers look like ordinary flowers that have violet petals. Early stages of night howlers are root bulbs, which can be mistaken for onion bulbs.

Usage
The night howlers appear harmless but have deadly effects on animals exposed to them, causing the unfortunate victims to go savage. They are also able to affect animals that do not have a naturally violent or ferocious disposition, as evidenced by their ability to turn non-predator animals, such as otters and rabbits, aggressively.

Bonnie and Stu Hopps mentioned that Bonnie's brother, Terry, once ate one and went berserk, which scared Bonnie. Stu uses the plants to scare off bugs from his crops but has his children stay away from them to prevent exposure.

Bellwether orchestrated a plot to use them to make every predator savage, giving the illusion that they are biologically reverting back to their primal selves. One of her henchmen, Doug, uses his chemist expertise to modify the flower and his sniper aim to dart every predator. Duke Weaselton was payed to steal bulb roots of the plant for Doug to create night howler pellets.

After Bellwether was exposed and arrested, Dr. Badger created an antidote for the predator mammals, including Mr. Otterton, who was reunited with his wife.

Role in the film
The night howlers first appeared at Bunnyburrow where Stu uses them to scare off bugs away from his crops. When heard about they have a psychotropic effect on animals, Judy realized she made an error and rushed back to Zootopia.

After recoiling with Nick, the duo get information from Duke who was doing it for money. He states that he did it for Doug in an underground subway, which was filled with night howlers being used in experiments and they saw Doug liquefying them into a case.

At a museum, Judy and Nick discover that Bellwether is the mastermind, who, after getting them into a pit, fires a dart at Nick. The seemingly savage Nick appears to bite Judy but it is all an act. Bellwether stated that she's going to frame them like she did with Mayor Lionheart until they show her a pre-recording of her confession, just when the ZPD police arrive and arrest her.

At the end, Dr. Madge creates an antidote for the savage mammals, including Mr. Otterton.