Create a concept art illustration of an elderly, plump witch in three different poses, depicted in a whimsical, caricature style. The witch should have a large, spherical body with exaggerated, rounded features, emphasizing her chubby and endearing appearance. Her facial features should include classic witch elements--like a pointy nose, warty skin, and a friendly, twinkling eye--but with a gentle and heartwarming expression that makes her look very cute and approachable. She holds a crooked staff and is accompanied by a mystical bird, both designed to match her rotund and charming style. Her outfit and accessories should be rich in shades of violet, ranging from deep purples to soft lavenders, adding a magical and vibrant touch. The overall vibe should be playful and tender, with her plump figure, cute facial features, and whimsical accessories contributing to her adorable, cartoonish appeal. The background should be minimalistic, allowing her vibrant design and charming personality to take center stage.