Kria is the Russian spelling of a duck's quack, written as кря, and this clip is simply that single cry isolated for soundboards and short edits. Because it is so short, it travels easily between meme pages, prank compilations and chat stickers, where a one-word animal sound can stand in for a reaction without any dialogue. It stays in use for the same reason other animal noises do: it is instantly understood across languages, needs no context, and adds a light, comic interruption to otherwise ordinary footage.