"Triggers your greatest fear."
Kate Kane[src]

The Fear toxin is a powerful hallucinogenic drug created and used by Dr. Jonathan Crane as the Scarecrow. When inhaled, the victim hallucinates their own worst fears becoming a reality.[1]


The toxin is gaseous and, if released into the air or inhaled by the body, forced the victim's brain to trigger the fear of their worst phobia. Though the length of the effects could vary, it can be nullified by adrenaline.[1]


The Fear Toxin was developed by Jonathan Crane. Prior to being incarcerated to Arkham Asylum, Crane shared a canister of his toxin with August Cartwright to use for his torture.[1]

The Fear toxin spilling on the ground.

After Nora Fries shot Killer Frost with a freeze ray, Barry Allen and Oliver Queen came to help. Oliver tried to use his speed to throw a lightning bolt at Nora, but missed and knocked over a box containing the serum, causing the vials to shatter. Oliver and Barry then started hallucinating, seeing each other as Eobard Thawne and Malcolm Merlyn respectively.[2]

August Cartwright later used the fear toxin to torture first his son "Mouse",[3] then Alice, forcing her to hallucinate his deceased mother, Mabel Cartwright.[1]

Fear toxin is one of the components of Snakebite.[4]


  • Hallucination: The serum can cause strong hallucinations that are hard to dispel, as shown when Oliver and Barry didn't realize they were fighting each other until Batwoman knocked them out.



Season 7


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