The incident occurred in Terra Santa, a city in Pará located almost 1,000 km from the capital Belém.
The city's Health Department reported that the man recorded on video biting the animal was trying to save children from a possible attack in the river.
According to the Department, witnesses reported that the incident occurred on a farm near the Nascimento Community.
Locals reported that the man was under the influence of alcohol and had entered the river after noticing the presence of the anaconda.
Fearing a possible attack by the snake on children who were playing there, the man jumped into the river to scare the snake away and ended up having his arm wrapped around the animal.
The man suffered a serious injury to his arm, but according to the Department, he refused medical attention after reporting that he was not feeling any pain.
Experts say that humans are not on the snake's menu and that attacks are rare.

Source: Amazon Agency