From Wikipedia ~
Capybara
"The
capybara[note 1] or
greater capybara (
Hydrochoerus hydrochaeris) is a giant
cavy rodent native to
South America. It is the largest living
rodent[2] and a member of the genus
Hydrochoerus. The only other
extant member is the
lesser capybara (
Hydrochoerus isthmius). Its close relatives include
guinea pigs and
rock cavies, and it is more distantly related to the
agouti, the
chinchilla, and the
nutria. The capybara inhabits
savannas and dense forests and lives near bodies of water. It is a highly social species and can be found in groups as large as 100 individuals, but usually lives in groups of 10–20 individuals. The capybara is hunted for its meat and
hide and also for grease from its thick fatty
skin.
[3] It is not considered a threatened species."
Apparently, it was revealed in some news outlet that Jennie liked capybaras because they were one of her favorite animals, so somehow YG was able to have one in the Ice Cream MV. I'm assuming a local zoo in Korea had some and one was borrowed from them.
Also, they are known to be friendly animals, and that's why she was able to get close enough to feed a carrot in the MV.