George Clooney Rides Donkey Alongside Brie Larson

George Clooney's just sittin' around on his ass -- alongside Brie Larson -- and getting paid for it ... good work if you can get it!

The movie stars were riding through the streets of Madrid Wednesday -- Clooney on a beautiful white donkey, and Larson on what looks like a white horse, of course. Although it could be a mule. Forgive us ... we're no equine experts.

Either way, they seemed to vibe well with the animals, and at one point, George even shared a moment with a chicken that wandered onto set. The actors were shooting a new ad for Nespresso. George has been its main spokesman since 2006.

Over the years actors like Matt Damon, John Malkovich, Danny DeVito and Natalie Dormer have joined him for the spots ... and now you can add Captain Marvel to that list.

Y'know what they say -- work hard, bray hard.