I didn't get to read that chapter so i don't have any ?'s
Answer:
What do you need help with good sir?
A hall defender does not describe Grendel in Beowulf. The answer is letter A. He is actually God cursed, terror monger, death dealing monster or beast that devours anyone he sees at night. He is huge enough to topple the size of a regular Anglo-Saxon. He is only defeated by Beowulf through sheer manpower and weapons since Grendel has nothing but his strength.
Your question is bit unclear.
Contrasts are differences and the two major differnces stated are there migration distance and what they eat to D long distance flying and feeding habits would be correct