When you venture into the southeastern part of Nebraska, stop and take a look at
Fairbury (Neb.). Then contemplate where the school got the motivation to be the Jeffs.

Photo courtesy of Fairbury Public Schools
When you're done, you'll likely have two answers.
The first possibility is one that makes perfect sense in a simple fashion. Fairbury is the county seat of Jefferson County. No questions necessary there.
But it's the second possibility that makes the Fairbury Jeffs one of the nation's more interesting mascot names.
The logo for the school features a man wearing a top hat, mustache and a suit that isn't exactly brand-new. And that is the same exact look as a character in the first daily comic strip, which began in 1907.

Photo courtesy of Astoria Oregon Rust
"Mutt and Jeff" were two men described as "Tinhorns" who like hanging out at horse racing tracks. The comic strip evolved into Jeff being Mutt's partner in rarely successful get rich quick schemes. Jeff, a very short man and bald with mutton-chop sideburns, got away from an insane asylum. He has no last name and says his name is "Just Jeff - first and last and it's always Jeff."
The similarity between the mascot logo and the character in the comic strip is undeniable. What is deniable is the exact reason for the mascot name and logo, as a definitive answer does not exist anywhere online.