goku
Almost every storyline in Dragon Ball boils down to waiting for Goku to get in the fight and beat up the big bad, but it's easy to forget that the series' main protagonist rarely murders his enemies. Goku let Frieza slice his own goofy ass in half (while Future Trunks finished off Frieza in his Cyborg form), and Cell hit his own self-destruct button. The fact remains that, throughout Dragon Ball Z, Goku only kills two people
Both events occur during the Majin Buu arc. The first was Yakon, a low-level miniboss whose gimmick was devouring energy. All Goku had to do was overload him, like flexing to pop the bloody bowels of a pesky mosquito.