The eight-second video shows Gyllenhaal holding up Amazing Spider-Man #311 (a classic), which featured Mysterio's return to the Wall-Crawler's life. He captioned the post, "I just realised I'm not playing Spider-Man".
Ahead of Saturday's rumored new trailer, a look at the Spider-Man: Far From Home costumes comes from the Brazil Comic-Con has hit the net.
Ohio State's Urban Meyer to Retire from Coaching
Meyer was making a reported $4 million per year while coaching the Gators; he signed a contract with the team worth $24 million. The announcement Tuesday immediately led to more guesses about where Meyer could end up coaching next season or in the future.
The main characters from Homecoming will all return, with Tom Holland of course reprising his role as Peter Parker/Spider-Man, Zendaya returning as Michelle Jones, and Jacob Batalon returning as Ned, while Marissa Tomei will also return as May Parker.
Gyllenhaal had been rumoured to be in the film and confirmed the news on Instagram on Wednesday.
Spider-Man: Far From Home will mark the 37-year-old's first comic book movie. It's now unclear which incarnation of Mysterio Gyllenhaal will be portraying. He's always been a particularly ridiculous villain - who can forget his iconic, screechy voice from the '90s animated Spider-Man series - so making him a real-world threat will be a challenge in and of itself. The alter-ego of Quentin Beck, Mysterio a special effects wizard and stunt man who decides to give up on his Hollywood ambitions and put his skills to use as a supervillain.