Summon the Sinister Six
The appearance of Adrian Toomes, a.k.a. the Vulture, definitely isn't an Easter egg, but it takes a real comics fan to spot some of Spidey's other legendary foes. While the Sinister Six has taken many forms over the years, the elderly Vulture has usually been a core member (with a younger Vulture occasionally standing in). Also pretty prominent in Homecoming is Shocker, whose villain name is mentioned a few times—and whose power isn't electricity, as one might guess, but shock waves generated by a technologically enhanced suit. In Homecoming, Shocker is whoever's wearing an alien-tech-enhanced glove, but the reference to the comics' Shocker goes twofold when those guys are seen wearing the same distinctive, yellow quilted fabric that the comics villain wears.
You'll find Mac Gargan, a.k.a. Scorpion, played by Better Call Saul standout Michael Mando. While big-screen Gargan seems to be a career criminal, comic book Gargan started out as an investigative reporter whose life is messed up by an experimental process that gives him super-strength and leaves him outfitted with a giant, mechanical scorpion tail. But if there was any doubt that these two Gargans were the same person, the cinematic Gargan's hatred for Spidey is revealed in the movie's mid-credits scene. Oh, and there's that giant Scorpion tattoo on his neck, too. That's probably a hint. It's also worth noting that in the comics, Gargan also served a stint as Venom, a character who's getting his own solo film in 2018.
Is that enough Sinister Six for one movie? Apparently not. While we don't get the ridiculous dome-headed Mysterio or the guy who wears a lion's head as a shirt, Kraven the Hunter, we do get a whole lot of Hobgoblin—and sorry to say, it's Peter Parker's biggest fan and best friend, Ned. While his full name is never given anywhere in the film, Ned's last name has been listed as 'Leeds' in a few different publications. In the comics, Ned was Betty Brant's husband and a reporter at the Daily Bugle, and saw his life ruined after he was brainwashed by the original Hobgoblin, Roderick Kingsley, to take his place. Needless to say, that story didn't end well for Ned; here's hoping his big-screen counterpart follows a different path.