“Elves.”

Singular- Álf
Plural- Álfar

Types of Elf:

Light elves
Singular- Ljósálf
Plural- Ljósálfar

Dark elves (possibly another name for dwarves)
Singular- Dökkálf or Myrkálf
Plural- Dökkálfar or Myrkálfar

Black elves (possibly another name for dwarves)
Singular- Svartálf
Plural- Svartálfar

“Dwarves.”

Singular- Dvergr
Plural- Dvergar

“Giants.”

Singular- Jötunn or Þurs (Thurs) or Risi
Plural- Jötunar or Þursar (Thursar) or Risar

female.
Singular- Gýgr or Íviðja
Plural- Gýgjar or Íviðjur

Types of giant:

Clay giants.
Singular- Leirjötunn
Plural- Leirjötunar

Fire giants. (live in Muspelsheim not Jotunheim)
Singular- Eldjötunn
Plural- Eldjötunar

Frost giants.
Singular- Hrimþurs
Plural- Hrimþursar

Mountain giants.
Singular- Bergrisi
Plural- Bergrisar

Sea giants.
Singular- Sjórisi
Plural- Sjórisar

Wind giants.
Singular- Vindþurs
Plural- Vindþursar

“Vanir”

Singular- Vanr
Plural- Vanir

“Aesir”

Singular-  Ás
Plural- Æsir

Female
Singular- Ásynja
Plural- Ásynjur