Chibi Trunks is Young Trunks put into different words. Trunks at this age was best friends with Goku's second son Goten. They both got in much trouble, but Trunks was the mischevious one. He got both of them in trouble all the time. Trunks was also able to go SSJ at the early age of eight. Trunks is the first son of Bulma and Vegeta. Trunks is able to fuse with Goten at any given time. When the fuse, they do a strange dance that signafies that they are fusing, and....1...2...3..
POOF, they create Gotenks.