List of ugly looking birds with pictures:
Potoo
Capuchinbird
Southern Cassowary
Marabou Stork
King Vulture
Helmeted Hornbill
Shoebill
Northern Bald Ibis
Turkey
Helmeted Guineafowl
Muscovy Duck
Marabou Stork
White-headed Vulture
Cinereous vulture
Sri Lanka Frogmouth is the ugliest
California Condor
Vulturine guineafowl
Greater adjutant
Southern ground hornbill