Vintage Fitz and Floyd for Neiman Marcus robin mug

Perhaps you’re a birder? Or a Wisconsinite that loves their state bird? In my neck of the woods, seeing a robin is the quintessential first sign of spring 🤩 this mug is a little more dainty/lightweight than a traditional ceramic mug, however I can’t confirm or deny whether it is porcelain. I do love the olive interior, though.