2. 'Savage' Hulk
A toy started this rumour, and it didn't take long for some sites and fans to back it up. An advertisement for a Funko POP! action figure featured all of the characters from Avengers: Age of Ultron given the bobblehead treatment, but the one which stuck out like a sore thumb was the grey 'Savage Hulk'. Was this a fun variant, or a huge spoiler from the movie? It appeared to be the latter, as there were later reports of the comic book featuring the advert being recalled by Marvel. Based on the trailers, fans have theorised that the Hulk is being controlled by the Scarlet Witch when he battles the Hulkbuster, while others are under the belief that it's Ultron controlling that massive suit of armour, rather than Tony Stark. According to rumours, it's during that fight that the green Hulk will transform into his Savage grey self, something which would obviously result in some major characters for the character in the Marvel Cinematic Universe. After all, fans are expecting Planet Hulk, but what if they're going to get Mr. Fixit Hulk in Las Vegas instead? You never know with Marvel Studios...