Goten
Goten is the second son of Goku and Chi-Chi. Goten doesn't come until the later part of the GT series though. Goten is the youngest saiyan to turn super saiyan. One day his older brother Gohan took him outside to teach him how when he suddenly did it right before his eyes at the age of 7. Another stipulation of this saiyan is that he can only reach SSJ1 for some reason. Can you see the family resemblance?