wearg

wearg, m.n: (for humans) villain, scoundrel, felon, criminal; (for non-humans) malignant creature, evil spirit. (WEH-arg / ˈwɛarg)

orcen

orcen, n: sea-monster. (ORK-un / ˈɔɹk-ən)

Possibly related to Icelandic orkn (a kind of seal).

wyrm, n: worm, insect, snake, dragon, reptile. (WUERM / ˈwyrm)

sceadu-genga, n: shadow-walker, one who walks in darkness (an epithet for Grendel). (SHEH-ah-duh-GENG-ga / ˈʃɛa-dʌ-ˌgɛŋ-ga)