Informal italian way of greeting someone, used by nobody but still very popular among italian people. It became a meme back in 2017 when Pewdiepie said it in one of his videos. It is also an intro-phrase used by the famous italian youtuber "Favij".
Nobody:
Pewdiepie: "Bella a tutti ragazzi... What did I just say? A BeAuTifuL iTAliaN GiRl?"