Hrym is the leader of the giants. He is the first enemy to present himself, but will not be the last.

Voluspa - Norse Mythology Book - Verse 50

“From the east comes Hrym |  with shield held high;

In giant-wrath |  does the serpent writhe;

O’er the waves he twists, |  and the tawny eagle

Gnaws corpses screaming; |  Naglfar is loose.”

Bellows Translation