Marvel Cinematic Universe: Definitive Guide To Easter Eggs, In-Jokes And Foreshadowing

Thor: The Dark World

25. Odin's Ravens

After background appearances in Thor and The Avengers, Hugin and Munin get a more prolonged cameo, their flight reintroducing the audience back to Asgard. They still don't do much in terms the plot, but given their prominence in Norse mythology, particularly the event of the subtitle, that could change come Thor: Ragnarok.

24. A Billboard Says References An In-Joke From The Original

As Jane and Darcy drive through London, a billboard can be glimpsed asking "Is Your Journey Really Necessary?" Ignoring the ineffectiveness of such an advert, this is a callback to a similarly obscure in-joke from the first Thor.

23. The Aether

After the Tesseract and Loki's staff, the Aether is the third Infinity Stone introduced (although the stone term is being used rather loosely). Which of the six gems (Mind, Soul, Power, Space, Time and Reality) from the comics it is, however, isn't clear; given its powers, Soul would be likely, although that clashes with the backstory of a character soon to be introduced.

22. Odin Alludes To The Infinity Stones (For The First Time)

In describing the Aether, Odin provides the first canon mention of the Infinity Stones (here just called relics and stones), hinting that the Aether and other mystical plot devices are, in some form, connected: "while the other relics often appear as stones, the Aether is fluid, and ever changing."