What evil creature makes a surprising appearance in Narnia?  What term does Poggin use for this creature

It was a grey thing with the head of a bird, Like some bird of prey with a cruel curved beak.  It had four arms which it held high above its head and it had twenty fingers, which were curved like its beak and had long, pointed, bird-like claws instead of nails.

Poggin used “demons” to describe this creature.

When Jill expresses a longing to visit Narnia in happier, more peaceful times, how does Jewel the Unicorn comfort her?  

Narnia was not always stirred and upsets. Between their visits, Narnia was so happy that notable dances and feasts or at most tournaments for thousands of years. The children were brought into Narnia only when there are bad things for Narnia.  And Jewel also comforted her that the good, ordinary times of Narnia would not have an end, and it just went on.

Farsight the Eagle brings more bad news later, including the dying words of Roonwit, the Centaur.  What message did Roonwit send?  

The message is that “  to remember that all worlds draw to an end and that noble death is a treasure which no one is too poor to buy." From King’s reflection, this message might mean the Narnia is no more and it would be in wars.