Wrocław, Poland - January 07, 2026 A zoo in Poland has shared video showing a tiny Chinese muntjac deer boldly confronting a huge rhinoceros inside a shared enclosure. The footage released by Wroclaw Zoo shows the small deer, named Mundzak, facing off against Marusia, a female rhinoceros weighing about 1.7 tons, as the two animals meet in the same outdoor paddock. Zookeepers explained that Mundzak’s aggressive behavior was caused by an excess of testosterone, as his female partner is currently in heat. The deer was attempting to protect his territory despite the massive size difference. “He needs to release his energy and show who's boss -- even if his sparring partner weighs 1.7 tons. Who would have thought that such a warrior could be hidden in that tiny body?” the post said. According to Wroclaw Zoo, Marusia is a greater one-horned Indian rhino born in 2014 in Plzeň, Czechia, who arrived from Touroparc Zoo in France in 2019. A pair of Chinese muntjacs have lived in the Terai pavilion since 2012, when the Asian fauna exhibit opened. The zoo said Marusia shares her enclosure with gibbons and Chinese muntjacs, using separate off-exhibit areas while sharing an outdoor space. Marusia treated the encounter as play, while for Mundzak it was a serious attempt to defend territory. She was described as gentle and aware of her size.