Nicknamed "Yuki-Chan" by Snow herself. A Guardian ÄRM snowman that can multiply itself and can reform even after being completely destroyed. When in its inactive necklace form, it appears to reflect Snow's emotion. Snow's favorite ÄRM, she can summon multiple snowmen at will.
Snow's father also owns this ÄRM. It is very large, has a moustache, and is called Kaiser Snow. So possibly he named his daughter after his Snowman or he named the Snowman after her.
"Yuki"-chan simply means "Snow-chan" since "yuki" is the Japanese term for Snow. Whereas its owner, Snow herself, actually has the English word for snow as her name.
Snow's counterpart Koyuki also has "yuki" as the latter part of her name.