View of crocodiles in the pool of a private farm belonging to the Rosenthal family in the San Manuel municipality, Cortes department, 220 km north of Tegucigalpa on Nov. 18, 2015. Getty Images

It was a sight not to be missed for a couple who had gone to Kruger National Park, South Africa. Mervyn Van Wyk, 72, along with his wife, Tokkie, came across a tug-of-war scene between a crocodile and a wildebeest. Van Wyk shot a video of the entire act in which the poor antelope is being shown getting attacked from below.

For about eight minutes, the herbivore struggled to get rid of the reptile's grip, but in vain, National Geographic reported. As the drama unfolded, other animals also gathered, watching the action.

In the video, the crocodile is seen to be dragging the wildebeest under water. These reptiles have long, heavy bodies and stubby legs, which is an advantage over large prey like wildebeest when under water, according to National Geographic.

As the wildebeest begins to tire from the struggle, two hippopotami approach the scene from behind. Suddenly, the duo target the crocodile and one of them helps the wildebeest to get out of the water. Although the mammal was set free, it was limping, which means that it is uncertain whether it would survive for long.

Van Wyk said in the Youtube post, according to the Independent: "You could see the exhaustion that the poor wildebeest was experiencing. I then noted what I thought were more crocodiles approaching but then saw it was actually two hippos."

"The hippos approached the scene cautiously and then suddenly sprang onto the croc forcing him to release his grip on the wildebeest. This amazingly allowed the wildebeest a chance to escape even though he had a broken hoof," he added.

Van Wyk also added that it is possible that hippos were showing their territorial behavior in contrast to rescuing the wildebeest, which is what many will think on watching the video. "Hippos don't like sharing their turf and might have seen the wildebeest as an intruder."

Douglas McCauley, a National Geographic explorer, and professor at the University of California, Santa Barbara, also agrees with this theory. He said that although hippos are herbivores, they can be extremely aggressive. He gave an example of a sleeping hippo in Kenya who attacked a lion when the former got disturbed by the big cat, National Geographic reported.

McCauley came up with two theories regarding the hippos' act in the video. According to his first theory, the crocodile had intruded too close into the hippos' territory, which made them aggressive. Both hippos and crocodiles frequent watering holes and are wary of each other.

His second theory suggests that the wildebeest's splashing prompted them to claim their territory. He also thinks that this hypothesis was more likely in this case.

"My best guess is that the hippos are acting very aggressive toward anything that tries to enter the water. They'll come charging in and try to drive you away," he said.

There have been several instances of these in nature where a hippo apparently rescued an animal being attacked by a crocodile. In a similar such incident in September 2014, a video that showed a hippo saving an antelope from a crocodile went viral. Even then, the antelope was being dragged slowly under the water by the reptile, but suddenly, a hippo rushed to save the animal.