Goten is Goku's second son, and a dead ringer for Goku when he was a
little kid. At the end of the series, Goten was 17 and looked nothing
like Goku though. Goten is very powerful for someone his age, although
he is a little bit naive like his father. He can fuse with Trunks to
become Gotenks, one of the most powerful characters in the series.
