The Star Gene - How to get a Shiny breedable or Baby Pokemon plus Ditto and Mew
Trade a Red Gyrados (or another Shiny) to R/B/Y and teach it Mimic (TM 31), then trade back. Go to Blackthorn and delete all its moves but Mimic. Trade back again and fight a wild Ditto with Gyrados. Let it Transform into your Shiny. Mimic Transform. Make your Gyrados use Transform. Ditto will Transform again. Then, capture it! Trade it back to G/S/C and breed it. Your odds of a Shiny are now 1 in 64!