Dr. Spencer Smythe is a classic Spider-Man villain who creates a legion of Spider-Man-killing robots called the Spider-Slayers. With Peter likely to be on the run at the beginning of Spider-Man 3, it would make sense for a group of robots intent on killing our favorite wallcrawler to be featured in the film. It would also make for a change of pace if Spider-Man 3 goes full Spider-Verse storyline, posing threats to all version of Peter in a similar fashion to Morlun and the Inheritors.
According to Charles Murphy of Murphy’s Multiverse, Spider-Man 3 is rumored to featured Dr. Spencer Smythe and the Spider-Slayers as villains in the film.
Murphy speculates that Smythe’s connection to J. Jonah Jameson, who was revealed to be making a return at the end of Spider-Man: Far From Home, could add some credence to Smythe and the Spider-Slayers inclusion. Murphy states that this could make Jameson a true threat to Peter, as opposed to a lower-level nuisance
Murphy also notes that B.J. Novak played Alistair Smythe, Spencer Smythe’s son, in The Amazing Spider-Man 2. With Electro potentially returning as the same version from that film, this could tee up Smythe’s inclusion in Spider-Man 3.
How this will have interplay with the inclusion of Electro is unknown. Perhaps these villains will be the first of many to show up, with more villains coming out of the woodworks to try their hand at hunting down Spider-Man. Having J. Jonah Jameson in a more active role working with Dr. Spencer Smythe could make for an interesting dynamic, allowing him to have a more direct impact in taking down the webslinger. Perhaps Jameson will continue his tirades and takedowns against Peter, enabling Smythe and the Spider-Slayers to have more public backing in their pursuit of Spider-Man.