Even given the fact that the Avengers movie is over two years old, Avengers mash-ups are still abound. This one combines two very different things to create a mash-up that is cool, cute and funny. By combining the world famous Pokemon series with the newly famous Marvel Avengers, you get something timely and iconic.
In this image, we see the Pokemon take on the roles that suit them best. Pikachu uses his thunder and lightning to take on the mantle of Thor, Charmander uses fire to become Iron Man and Squirtle uses his blue color to become the Captain.
It's a clever use of both franchises all rolled up into one image, but what's curious is that the Pokemon trainer in the image is Nick Fury, but takes no cues from Ash Ketchum in the series.