Apollo gets mentioned whenever there's a Kentucky Derby contender who didn't compete as a juvenile - like Verrazano, one of this year's favorites. Apollo won the race in 1882 and remains the only Derby winner without any starts at 2.
"Some fools think he's a right smart horse, though he ain't," was the assessment of Green B. Morris, Apollo's trainer and co-owner, when asked about his Derby chances in early 1882. But Morris wagered heavily on Apollo in the Derby winter books.