Footage shows the intoxicated 23-year-old visitor jumping into the water at the enclosure at Warsaw Zoo, and after a female bear follows him in, he can be seen wrapping his arms around her neck and seemingly holding her head below the water.
Fortunately for the man, he was rescued by firefighters and taken to the hospital with only minor scratches. However, zoo spokesperson Anna Karczewska said the bear was left badly shaken by the incident.
She said: "The female bear, named Sabina, was surprised by the man's actions and is now sitting in the water and nervously roaring every now and then. She is under the watchful eye of caring zoo staff."
The zoo added that it will do all it can to see the man prosecuted.
According to Polsat News, the zoo said: "The Warsaw Zoo will take all legal steps related to this event to bring the perpetrator to justice. The animals were exposed to danger and their psychological comfort was disturbed."
In an emotional Facebook post, the zoo claimed the man 'drowned' the bear, named Sabina, and that his intrusion could have led to her being shot.
The post read: "Loved ones. Today won't be funny or fun. Today is going to be very serious. Probably some of you have already heard about the incident on the catwalk of brown bears in Prague Park. In broad daylight, a man jumped on the catwalk where two of our bears jumped in the influence of our bears [sic].
"He attacked Sabina, then drowned her in the water. Everything ended 'well' - and human and animals are alive. Sabina escaped and the intruder pulled out by the Fire Brigade. However, this is a terrible tragedy for us.
"Little One [another bear in the enclosure] was also on the catwalk at that time, luckily she did not join the whole fight. If that were the case, a man could have suffered much bigger injuries.
"For us, however, the biggest nightmare is that in situations like this, when human life is threatened, animals are shot. The sedatives don't work fast, only firearms are left. Maybe not everyone knows this and that's why they risk to pet, feed, take a 'cool' picture and be able to show off on the internet."
While the incident ended about as well as it could have, the zoo added that Sabrina - who was rescued from the circus - was left stressed and anxious in the aftermath.
The post continued: "It broke our hearts that Sabina survived this attack hard. She was stressed out for a few more hours, cried and didn't respond to our calls. She is already an aged bear, rescued from the circus and has passed her in her life.
"We work with them every day making sure that together with Little One they trust us, are not afraid of us and feel comfortable. Is it really worth it, for a 'cool' video, photos, or out of pure stupidity to destroy everything we have achieved? We can't think for others. Remember, everyone is responsible for themselves.
"If things were a little different, Sabina and Little One might not be with us anymore. And this is the scariest thing about all of this."