Highly detailed vintage retro vinyl sticker illustration of a grumpy hedgehog curled into a defensive ball, only its scowling face poking out with furrowed brow and squinted unimpressed eyes, tiny pointed nose, small front paws tucked under chin. Intricate spike rendering with hundreds of individual fine pointed quills covering the body in radiating pattern, detailed cross-hatching at the base of each spike, soft fur on the face with parallel hatching, whisker details, small ears barely visible above the spikes. Tiny exclamation marks or anger symbols around the head. Bold curved arched text "INTROVERT" above the hedgehog following a half-circle path and "BY CHOICE" curving below in matching half-circle, in bold condensed slab serif font. White background, professional black ink illustration, vintage engraving aesthetic, no border, no frame, isolated illustration centered composition.