3. The Hulk Goes Grey
Like so many rumours before it, this one originated from a toy. By now, you would think that people would know better than to take the word of any merchandise, but the reveal of a "Savage" Grey Hulk from Funko saw a number of sites soon "confirm" with their sources that this version of the Green Goliath would be appearing in Avengers: Age of Ultron. However, this was just a special edition variant bobblehead, so why anyone seriously thought that meant Grey Hulk would be in the sequel is hard to say (especially as a very green version of the character had been seen multiple times in trailers by this point). This is another example of how misinformed so-called "insiders" are, because an ILM VFX video released after Age of Ultron confirmed that they considered turning Hulk grey for his battle with the Hulkbuster at a very early stage in production. By the time this rumour surfaced, that was a distant memory, and sites clearly based this rumour on the toy alone.