She was derived from the Mesopotamian goddess Ningal, and like her forerunner was regarded as the spouse of a moon god, whose precise identity varied between locations.

Nikkal was derived from the Mesopotamian goddess Ningal (Sumerian: "great lady"), wife of the moon god Nanna.

[5] Similarly to deities such as Ea, Damkina, Aya or Pinikir she was introduced from Mesopotamia to Hurrian areas possibly as early as in the third millennium BCE.

[6] Alfonso Archi assumes that the presence of Ningal in the pantheon of the kingdom of Mari in particular was in part responsible for her adoption by the Hurrians and her later prominence in their religion.

[12] However, restorations of Ugaritic texts including the phrase ilat inbi, "goddess of fruit," are now regarded as erroneous and there is no evidence that such an epithet was ever applied to Nikkal independently from the name Nikkal-wa-Ib.

[12] An alternate interpretation associates Ib with Umbu,[5] a name of the moon god in Hurrian sources which possibly originated in Upper Mesopotamia.

[19] Piotr Taracha [de] notes that it can be considered an example of a broader phenomenon of worship of dyads of deities in Hurrian religion, and compares this case to the pairing of deities such as Ḫepat and Šarruma, Ninatta and Kulitta, Hutena and Hutellura, Išḫara and Allani or two hypostases of Nupatik in cultic context due to their similar characteristics.

[20] Volkert Haas suggested that they were divine prophetesses, and interpreted their name as an Akkadian loanword in Hurrian based on the similarity to the terms maḫḫitu and maḫḫutu(m) attested in the Mari texts.

[21] A ritual attributed to queen Nikkal-mati lists various further deities who belonged to the circle of Nikkal, including Zēdu (possibly her divine handmaiden), Alwil, Agaššari, the "gods of the father" of Nikkal,[b] as well as other groups of deities not provided with individual names (širini, ḫawari and gate) divine hounds and piglets.

[30] In the Kizzuwatnean ritual of Ammiḫatna Nikkal is among the goddesses mentioned in the context of offerings made to all the female deities (Hurrian: ḫeyarunna aštuḫina).

[44] During a ritual which took place during the final month of the Ugaritic lunar calendar, Ra’šu-Yêni ("first wine"),[45] she received a cow as an offering directly after sacrifices to Yarikh.

[48] A treaty between Ugarit and Carchemish indicates that Nikkal was also worshiped in two other nearby settlements, Gur'atu and Nubannu, both of which were under the control of the latter kingdom.

[49] According to Gina Konstantopoulos, it is possible that a reference to Nikkal which she compares to the attestations of this goddess from Ugarit might be present in the treaty between Ashur-nirari V of Assyria and Mati-ilu of Arpad from the first millennium BCE, which invokes many western deities, for example Hadad of Aleppo, Karhuha and Kubaba from Carchemish or Melqart and Eshmun from Phoenicia, alongside Assyrian ones.

[15] After showing he is willing to offer a large amount of silver, gold and lapis lazuli and promising that he is capable of siring a child he secures a permission to marry Nikkal.

[55] It has been proposed that a poorly preserved section of the text describes a sexual encounter between Nikkal and Yarikh, but this remains uncertain.