Bacterian

Bacterian is a massive, filthy fighter who competed in the 21st World Martial Arts Tournament. He has allegedly never bathed in his entire life, using his overwhelming body odor and general uncleanliness as weapons to incapacitate opponents.

Krillin defeated Bacterian in the preliminary rounds of the 21st World Martial Arts Tournament. Bacterian initially dominated using his body odor, but the turning point came when Goku reminded Krillin from the sidelines that he does not actually have a nose, after which Krillin became immune to the smell and finished Bacterian with a powerful kick.

Bacterian relies on one of the most unconventional fighting strategies in Dragon Ball history: hygiene so poor that it functions as a biological weapon. His body odor is potent enough to stun opponents from a distance, and his various attacks involve weaponizing his own filth in creative and disgusting ways.

Bacterian makes a brief reappearance at the 22nd World Martial Arts Tournament but is eliminated early. His character exists purely as a comedic obstacle, representing the original Dragon Ball's fondness for gross-out humor and absurd fighting gimmicks.

Krillin's character design famously gives him no visible nose, a recurring joke in the series. When Goku reminded him of this during the fight, Krillin realized he had no actual nose to be overwhelmed by Bacterian's odor and quickly defeated him with a powerful kick.