We'll freely admit that this is an incredibly, unbelievably deep Easter Egg and we didn't even clock it the first, second or even third time we watched Avengers: Age of Ultron.
Joss Whedon is known for adding little hints, references and callbacks to his previous works in some of his film, but Age of Ultron had one that escaped us completely.
Remember the scene in Ultron when Thor is shown Asgard as a sort of, well, orgy? He meets Idris Elba who's all drunk and his eyes are white and there's people dancing everywhere and it's all very Eyes Wide Shut / Dance Cavern from Matrix: Reloaded.
Anyway, there's a little flash of these three figures with the head of a wolf, a ram and a stag. What's another word for a stag? Hart. So, when you see the three of them together, it's Wolf - Ram - Hart.
Still not getting the reference? Not a big Buffy or Angel fan, huh?
Wolfram & Hart were the bad guys from Angel, a high-powered law firm that was also a front of demons in Los Angeles. So, when you put those three figures, you get...
Yeah, like we said, it's tenuous and it's blink-and-you'll-miss it, but hey? Buffy / Angel references. That's something you don't see every day.