Warning: contains spoilers for Fantastic Four #37!

While Peter Parker has been Marvel's official Spider-Man for over 50 years, he's already been replaced by Miles Morales. Widely considered the company's most popular and most successful hero, Spider-Man is the classic teenage superhero, introduced by Stan Lee and Steve Ditko at a time when superheroes were exclusively portrayed by adults; any teenagers involved were either ordinary, non-powered citizens or ineffectual sidekicks at best. But in Fantastic Four #37, written by Dan Slott with art by Nico Leon and colors by Dono Sánchez-Almara, even the citizens of New York believe the 'old' Spider-Man is no longer the city's hero.

Miles Morales began as a character entirely separate from the main Marvel continuity (the so-called 616 universe), hailing from the Ultimate Marvel universe. In the Ultimate universe, Peter was actually killed during battle, and Miles became the new Spider-Man, but was eventually migrated to the main canon in 2015. From there, he's since made a name for himself fighting alongside other similar heroes like Peter Parker and Kamala Khan, the new Ms. Marvel. His powers make him distinct from Peter as well, with the ability to venom-blast enemies (stunning them temporarily) and camouflage into his environment.

Related: Spider-Man Theory: Peter Parker is Finally Going Radioactive

In the Halloween issue of Fantastic Four, the Thing's children are out trick-or-treating (his daughter Nicki using her shapeshifting powers to acquire candy from the same house multiple times), when the Profiteer's battleship appears in the night sky, ready to take the children home. A fight ensues that's eventually joined by Spider-Man (who was in the neighborhood cheering up the Human Torch after Doctor Doom set him alight permanently). After the battle, two trick-or-treaters seemingly fail to recognize Spider-Man's costume. They insist he's not "...the real [Spider-Man] He's shorter and has red and white eyes." 

The children's description fits Miles Morales to a T. Miles is indeed shorter, and he recently acquired a new costume with an entirely different silhouette than Peter Parker's suit (the artist deliberately designed it in a way to be as visually different from Peter's classic suit as possible). Perhaps Miles is also patrolling the city more often and interacts with more people on the ground; considering Peter's previous adventures were largely self-contained, that could be an accurate assumption.

Miles Morales may be replacing Peter in another way very soon. In current Spider-Man comics, Peter is relegated to a hospital bed, his body suffering from what appears to be radiation poisoning. If Peter Parker loses his powers or is otherwise taken out of the fight through this incident, the mantle of Spider-Man could (and perhaps, should) pass down to Miles Morales.

Next: Spider-Man's Daughter Is The Best Thing That Will Never Happen To Him