Answer: DODOS

AnswerCrossword Clue
DODOSDumb bunnies
DODOSDumbbells
DODOSGrounded birds
DODOSGeniuses they're not
DODOSIdiots
DODOSStupid people
DODOSOld fogies
DODOSMauritian has-beens
DODOSFuddy-duddies
DODOSVanished creatures
DODOSExtinct flock
DODOSSlow-witted ones
DODOSLunkheads
DODOSBackward ones
DODOSDefunct birds
DODOSReal gone birds
DODOSFogies
DODOSOld birds
DODOSOld birds.
DODOSExtinct Mauritius birds
dodoslarge, extinct flightless bird
dodosDODO, an extinct bird
DODOSLost birds of Mauritius
DODOSExtinct, flightless birds
DODOSWiped-out avians
DODOSExtinct flightless birds
DODOSCritters extinct since 1681
DODOSBirds extinct by 1681
DODOSSome extinct birds
DODOSBygone birds.
DODOS"Ice Age" birds
DODOSMeatheads
DODOSDummkopfs
DODOSDim bulbs
DODOSBoneheads
DODOSRattlebrains
DODOSEinsteins they aren't
DODOSDim bulbs, so to speak
DODOSLong-extinct birds
DODOSResidents of Mauritius, pre-1662