|Anhima cornuta||Order: Anseriformes||Family: Anhimidae (Screamers)|
I’ve never seen this fairly common bird of wetlands of much of tropical South America. My photo is from Bill Bouton from San Luis Obispo, CA, USA, via Wikipedia. The Horned Screamer has a place in Guinness World Records:
Horned Screamer: Largest horn on a bird. Also known as the unicorn bird, the South American horned screamer (Anhima cornuta) has a curved horn measuring up to 15 cm (6 in) in length.