All pure-blooded Saiyans share several common features: All are born with the hairstyle they keep through out there life, all are very strong and muscular, and they all have a tail. The tail is a weakness for weaker Saiyans. As any pressure applied to the tail will temporally paralyzing a Saiyan ,but Saiyans who have strengthened their tail, are not affected by this at all . The tail is also necessary for the transformation to the Oozaru state. Also all Saiyans have a strong love to fight, which can stometimes be a weakness.