The Dragonflight world boss for the week of January 3rd is Liskanoth in Thaldraszus.
Liskanoth drops an armor piece of each type, and a cloak at ilevel 395.
Cloak: Frosted Scale Drape
Cloth Armor: Frozen Footwraps
Leather Armor: Glacial Bindings
Mail Armor: Horns of the Futurebane
Plate Armor: Icebound Girdle
Dragonflight features four world bosses, each elemental themed and rotating throughout the four expansion zones.