A recently spotted, but as yet unreleased poster for The Amazing Spider-Man 2 suggests that the wall crawler will face three enemies, including the Green Goblin. The picture of the poster was taken by Twitter user Jesser Piedra (and reposted by Comingsoon.net), and the timing seems to coincide with a new trailer Sony has confirmed will release on December 5.
In the image above, you can clearly see Electro, played by Jamie Foxx, along with two others. The image on the left appears to be a heavily robot-influenced Rhino, but that is unconfirmed. If it is him, it opens up another line of questioning/speculation.
The character of Spencer Smythe was teased to be in the film as an employee of Oscorp, via a mock Tumblr account for The Daily Bugle. In the comics, Spencer Smythe was the creator of the “Spider Slayers,” robotic constructs created (originally on the dime of J. Jonah Jameson) to capture and unmask Spider-Man. Smythe’s efforts eventually led to his death, prompting his son Alistair to take up his mantle and create more Spider Slayers.

The real eye opener on the poster is the figure on a glider that appears to be Green Goblin. There may be more to the story than that, and it may be a precursor to the Goblin, who will be introduced in a later film. Spider-Man has faced several “goblin” enemies, including the Hobgoblin and a recent Grey Goblin. Even if it is the Green Goblin, it isn’t clear which one.
In the comics, there have been multiple people to don the Green Goblin mantle, but the two that stand out are Norman Osborn and his son Harry. Both characters are in the film, played by Chris Cooper and Dane DeHaan, respectively. In both the comics and the Sam Raimi trilogy of Spider-Man films, Norman Osborn was the truly villainous character, while Harry generally followed later out of a misguided sense of loyalty influenced by a variety of reasons, including insanity.

The Amazing Spider-Man 2 on May 2, 2014. The trailer, however, debuts this week.
Update: We’ve replaced the image on top with a better, higher resolution image directly from the film’s official page that grants a clearer look at the villains. Most notably is the look at the Goblin (or goblin-like character), that bears more than a passing resemblance to Dane DeHaan. Check out the closer image on the right, and sound off in the comments with theories!