Answer:

loon

Answer	Crossword Clue
LOON	Diving bird
LOON	Guard of the Nibelung treasure
LOON	Minnesota state bird

LOON	Golden Pond bird
LOON	Minnesota State bird
LOON	Crazy fowl
LOON	"Crazy" bird
LOON	Fish-eating bird
LOON	Web-footed bird
LOON	Canadian coin bird
LOON	Craziness exemplar

LOON	Screwball
LOON	Symbol of craziness
LOON	Canadian dollar bird
LOON	Daffy bird?
LOON	Bird on a Canadian dollar coin
LOON	Canadian-dollar image
LOON	Crazy as a ..
LOON	Skilled diver

LOON	Ducklike bird
LOON	Minnesota's "crazy" state bird
LOON	Minnesota's state bird
LOON	Nut
LOON	Crazy bird?
LOON	Airhead
LOON	Bird on Canada's dollar coin
LOON	Epitome of craziness

LOON	Bird on a Canadian coin
LOON	Grebe's cousin
LOON	Bird in a crazy simile
LOON	Bird on the Canadian dollar
LOON	Simpleton
LOON	Nutso
LOON	"On Golden Pond" bird
LOON	Crazy as a ...

LOON	"Laughing" bird
LOON	Bird with an eerie call
LOON	Canadian coin flier
LOON	Creature on the Canadian dollar
LOON	Gopher State bird