the answers is Ostrich. Ostrich cannot fly but they are the fastest bird to run.
Ostrich
The ostrich is a bird that cannot fly at all, let alone fly backwards. It is the largest bird in the world and relies on its strong legs to run at high speeds to escape predators.
the biggest bird in the world is the ostrich, and it cannot fly
Bird can fly while the other animals cannot.
Emu
Its because fly is both a noun and a verb, so it can be done, and in this case a bird happens to be able to fly. But sadly, bird is a noun and not a verb, so you cannot bird.
Dodo, elephant bird, moa.
It means a bird that cannot fly, like a penguin.
The ostrich.
emus
Because it is a penguin.
Penguins