Actually these are Spectacled Caimans ( Caiman crocodilus ), with the location being Pantanal, Mato Grosso, Brasil. Photographer is possibly Wim van den Heever.

Although the caimans have some potential to tackle the world’s largest rodent (capybaras), they are evidently not their usual prey, which would be more like crustaceans, fish, small mammals, molluscs, amphibians and reptiles. That said, older caimans are evidently capable of taking down larger mammalian prey, such as wild pigs. So go figure.

Another relevant factor here would be that well-fed predators are routinely treated as harmless by other animals, and capybaras would be well-familiar with these blokies, living side-by-side as it were.

(right-click as needed)

https://www.mindenpictures.com/cache/pcache2/90717141.jpg

Yacare caiman (Caiman yacare) with a group of Capybara (Hydrochoerus hydrochaeris) These two species often sit together, using each other’s alertness to warn of potential dangers.

FUN FACT: The largest cavy in the world weighed over 2,000lbs!

https://static.wikia.nocookie.net/fossil/images/4/4a/Art_impression_of_Josephoartigasia_monesi.png

https://en.wikipedia.org/wiki/Josephoartigasia

https://www.prehistoric-wildlife.com/wp-content/uploads/josephoartigasia-size.jpg

Stay safe, fellow Fediversers!