Gyllenhaal is set to star as classic Spider-Man foe Mysterio in Far From Home, which is set to arrive in theaters on July 5.
Mysterio is a special effects expert who uses his skills to commit crimes by creating illusions. A trailer for Far From Home released in January, featured Mysterio coming into contact with Spider-Man in Europe as the villain started to battle a giant being made of water.
"The thing is, is like those are the actual green lasers that I shoot out of my hands," Gyllenhaal joked to Fallon about his apperance in the trailer. "That's what I can do, and that's why they hired me."