What do the following three-letter words have in common?
fat oak lax sat
den sea pit lit
Here's one solution... (but I doubt it's what DJ's looking for)
All the words can be transformed by replacing one of ANY of the three letters.
FAT SAT FIT FAR
OAK YAK ORK OAR
LAX PAX LOX LAB
SAT RAT SIT SAW
DEN HEN DIN DEW
SEA TEA SPA SET
PIT NIT POT PIN
LIT SIT LOT LIP