I've read about a guy name Felix Valencia and was simply just wondering who else has never lost. Anyone?
The main objective of most fighters at the gatherings is not to "win" or "lose" and the gatherings are not set up that way. The only possible criteria one could use to maintain that he was undefeated would be to have never tapped out, been KO'ed, or had to quit before time was called. With this as the criteria, there are probably scores of fighters who are "undefeated", although most of them would probably never make this claim.