Future Trunks:
He hits the scene at age 17 by traveling back in time. He does so with a bang by
destroying both Freeza and his father. But he came with a grim tale of the
future, a future where all the Dragon Ball Warriors were killed except for
himself and in a future dominated by two powerful cyborgs #17 and #18.
Trunks traveled back in time hoping to change the future by changing the fate of
Son Goku. In his future, Son Goku died of a rare heart disease. He believed that
Goku was pivitol to the events of the future, so he brought the medicine
necessar to save his life. Even though his future could not be changed, he hoped
that the "present" will not turn out like his future.
In the end, he got more than what he had bargined for. Not only was he able to
completely change the events, but he also, under the guidance of Goku and Vegeta,
he became more poweful than he could imagine, enabling him to put right, his
future.
Chibi Trunks:
Like Goten, he was able to achieve Super Saiyajin at a very young age. Due to
the lack of available warriors, he performed a fusion with Goten into Gotenks to
battle Majin Buu.