Yamcha is first seen as an enemy in the beginning of Dragonball as Bulma and Goku are crossing through the desert where he lives and he tries to rob them. He and Goku fight, and it looks like he's winning, but then he sees Bulma and freezes as his intense fear of women kicks in, Puar ends up dragging him off and Goku wins. He follows them around them for a while, still trying to take the Dragonballs, but eventually becomes a good guy. He dates Bulma for a little while, but they eventually they break up.
In Dragonball Z, he is first seen as a Pro Baseball player, enjoying a little fight between rival teams. After Krillen tells him of Goku's death and the Saiyins, he trains on Kami's tower/house for a year and gets much stronger. But, he is the first to die in battle beacause the Saibaman he though was dead got him by suprise and self destructed, killing them both.
After this point, his role in the show dwindles down to almost nothing but a person standing in the background most of the time, and he is virtually no exsistant in Dragonball GT.
Power Levels and Attacks
Power Levels
--Dragonball--
21st Tenkaichi Bodokai
-73
Fight against the Uranai Baba's Team
-84
22nd Tenkaichi Bodokai
-128
23rd Tenkaichi Bodokai
-167
--Dragonball Z--
When Raditz apears
-177
Against the Saibamen
-1,480
Against Recoom(on Kaio-sama's planet)
-35,000
Appearance of the androids
-200,000
Cell game(after training in the Room of Spirit and Time)
-1,000,000
Attacks
-Rogafufuken: His trademark attack in Dragonball. He attacka using many punches with his hands shaped like claws. He finishes it off with a double "claw punch".
-Shin-Rogafufuken: An improved version of Rogafufuken. He gets this after training with Mutenroshi.
-Sokidan: His trademark attack in Dragonball Z. A round enery ball is gathered in his hand and flys around, confusing his opponent, until he wants it to hit them.
-Kamehameha
-Bukujutsu: Not really an attack, it's just flying. Almost everyone in DB can do this.
