Cottonmouth fully submerged swimming underwater.

The video likely performed well due to its niche subject matter (wildlife, specifically snakes) and the intriguing visual of a snake swimming underwater, which can be captivating for viewers interested in nature or herpetology.

The video shows a cottonmouth snake swimming underwater in a muddy creek. The snake is fully submerged and moving through the water near the bank, which is covered in roots and dirt.