Have a 2-5% chance to get a rare race when you pick:
Sayian - Legendary Sayian
Namek - Elder Namek
Alien - Coolor(get coolor transformations too)
Majin- Kid Buu
Or when you rebirth you choose to start off as a rare race
Rare races start with 3-4k PL 300-400Ki and 50-80 in each stat