actually, krillin mentioned it himself at some point in the series, he doesn't have a nose.Vince Carter said:He does have a nose it's the six dots he has on is forhead, and that's pretty funny Piccolo but you are true Uub is the strongest human, but this subject wasn't about that, it's about how Krillin became more afraid of fighting and is getting weaker.
I think the others were complaining about a horrible smell, and krillin joined in... then exclaimed WAIT I DONT EVEN HAVE A NOSE. ha ha ha.
I'm not quite sure of the details, but if i remember correctly it was during the dragon ball series, during one of the world tornements. Krillin was fighting an incredibly stinky man.