These were available from Subway only by unlocking all 6 heroes (i.e, getting the 6 codes off soda cups or chip bags to do so).
There are 8 different, but these are virtual cards only, so they are virtually pretty cool, as opposed to actually pretty cool, haha.
Enjoy!

Ultron


Nick Fury


The Mighty Thor


Black Widow


Hawkeye


Hulk


Iron Man


Captain America

They Look Great... Too Bad they are Virtual Cards.

In a past time they would have been real cards. Now fast food places rarely have promotions that are worth anything to a collector. I still have a bunch of stuff, including baseball cards, from McD and Burger King and Taco Bell, but practically nothing in recent years.

Subway actually did just do 6 nice Star Wars "Rebels" cards that were with the re-usable kid's meals bags.
They have the bags again for the Avengers, but it seems the cards have been replaced by the bag itself as the draw as it apparently transforms into some kind of 3-D playset. I'd have picked one up, but they don't sell them separately anymore, unfortunately (and I'm too big for a kid's meal, haha...)

Someone at work today had this cup, and let me have it when she was finished with the drink. I washed it out and put a couple of old cards I had laying around next to it for size reference:

Just "laying around" indeed. Those are some gems.

The code on the other side of the cup is what I entered to get those virtual cards I posted. There's also codes on the little baggies of chips they sell. The codes are on the outside of the bag for those dishonest folks with a good memory, haha. It's also an instant win game, but I didn't win anything.