Skin changes – Heimerdinger as a snowman with sledge turrets.. Specific in-game changes:

• Model: Major model changes for Heimerdinger plus new model for his tools and turrets..
• New particles: New candy bar for his auto-attack..

Skin bio & introduction: – Brought to life by the power of a magic hat, Snowmerdinger now pursues theoretical Snowdown sciences including snowball trajectory, cocoa cooling speeds, and automated turret construction. He engineered his own strain of carrot noses.

How to get this skin? – The skin is not available for purchase and has been placed in the Legacy Vault (they can still be mystery gifted, and only appear in a champion’s information tab if owned). The vault is usually opened for limited runs and this skin can then be purchased in the Riot Store. In my experience it can be rather long between each opening of the Legacy Vault, hang tight!

Worth buying? – Snowmerdinger is a Legacy vault skin — rarely available and not in the regular store. It includes custom particles. You can preview any skin for free on the PBE server before buying. Learn how to access the PBE here.