At least some content in this article is derived from information featured in Fantastic Beasts and Where to Find Them (film). As such, spoilers will be present within the article.
This venom was a substance extracted from a Swooping Evil that had strong obliviatory properties. While potentially very dangerous to come in contact with, if properly diluted, it can be used to remove bad memories.
When Credence Barebone wreaked havoc on the streets of New York as an Obscurus and revealed the secret Wizarding society to the No-Maj community, Seraphina Picquery thought it would be impossible to Obliviate an entire city. However, Newt Scamander suggested that they use the venom of the Swooping Evil with the help of Frank, a Thunderbird, which could create storms as it flew, to erase the memories of every No-Maj in New York. Seraphina agreed, and the Thunderbird created a storm of rain containing Swooping Evil venom to successfully salvage the secrecy of the Wizarding society.
Behind the scenes
- The fact that the venom is said to remove bad memories might explain how Jacob Kowalski was capable to recall Queenie Goldstein in his bakery at the end of the first instalment of Fantastic Beasts. Whereas the remainder of the No-Maj population in New York had experienced fear and catastrophe when the Obscurus terrorised the city, Jacob for his part was largely shielded from that aspect of the events by following Newt, and his discovery of the magical world and the wonders of magic left a strongly positive impression on him. Combined with the fact that he found new friends and even romance during these events, as well as his fondness for the magical creatures, the venom may have left much of these positive memories intact.
- Fantastic Beasts and Where to Find Them (film)
- Fantastic Beasts and Where to Find Them: The Original Screenplay