25 Best Easter Eggs & References In The MCU So Far

5. Captain America's Shield (Iron Man / Iron Man 2)

Although it was never really acknowledged or explained why it was there, there was a replica or prototype of Captain America's Shield clearly visible in Tony Stark's workshop in both Iron Man and Iron Man 2. In the first Iron Man movie, it could be seen behind Tony when he first removed his Iron Man armour and then, in Iron Man 2, it is visible when he is building a particle accelerator in the same workshop. At the time, Captain America hadn't had his own movie and, while it foreshadowed his appearance, it was unclear what the link to Tony Stark was. We later found out that Stark's father, Howard, had worked closely with Steve Rogers during World War II, but it was exciting to see the shield regardless.