On Madagascar, there lived the Elephant bird, extinct from at least the 17th century, who stood much taller than our modern day ostrich.
With a giant bird.
Dyna Bird :p
it is a mythical giant bird. Some say it was the largest living bird,
The Roc is a mythical, giant bird.
The Giant Ibis is the national bird of Cambodia.
Yes, the Argentavis which was basically a bird had to be a giant so that it would be able to catch the horse.
It is a mammal
Goliath is the name of a giant. It would be fine as a name for a big bird.
The Giant Moa.
Big Bird
In television series Family Guy, there is a giant chicken known as the Big Chicken.
Giant birds: The Dodo Bird, The Elephant Bird, and the Argentavis.