Originally posted by Bragdras:

The bird literally tells you to pick their brain

Giant remains
Munin: Giant remains Shadow of ancient age. The Jotunn once ruled the 10th world, until their time ran out and they were ousted by some other power.
Hugin: Kraa! Pick their bones and break their domes!
I see domes, which can means a lot of thing including the ribs that form the dome shape, I don't see brain though.