I was gonna chirp in with Matarazzo, but it's too easy. Who had shitty calf's as an armature and improved as a pro? That's a tuff one for sure, but I'd say Chick. He had little ones as an NPC athlete and now like magic......BAM
Arnold was so discussed with his calf development, he'd cut his sweats to show how small they were as inspiration to work extra hard to improve them and he did!