Volkert Haas proposed that Tašmišu's name was derived from the Hurrian word tašmi, which he translates as strong.[1] The suffix -šu is also known from the name of one Teshub's bulls, Šerišu, and various Hurrian personal names, such as Anniwašu or Ekammešu.[1]
Tašmišu was one of the multiple warrior gods in the Hurrian pantheon.[2] Other such deities were Ugur, Aštabi, Nergal and Ḫešui.[2]
In myths, his position appears to be that of a subordinate of his brother Teshub, and in one passage from the Song of Ullikummi he outright addresses him as "my lord."[3] He served as his sukkal (attendant deity), though as noted by Daniel Schwemer this role in ritual texts could also be attributed to the god Tenu.[4] He proposed that the latter was adopted from the religious tradition of ancient Aleppo,[4] where a month was named after him.[5] However, Alfonso Archi ascribes Hurrian origin to Tenu.[6]
Tašmišu was regarded as the "pure brother" of Teshub.[7] Their sister was the goddess Šauška.[8] Their parents were Anu and Kumarbi.[9] Tašmišu's wife was the goddess Nabarbi.[10]
Hittites identified Tašmišu with their god Šuwaliyat,[7] who had old Anatolian (Hattian) origin.[5] However, Tašmišu never acquired the latter's association with vegetation.[11] Both of them could be associated with Mesopotamian Ninurta.[5] As a result, instances where Tašmišu's name is written logographically as dNIN.URTA are known.[12] Another attested logographic writing is dURAŠ.[13] Furthermore, a god list from Emar identifies him with Papsukkal.[14]
In Hurrian offering lists, Tašmišu usually follows Teshub.[15] Worship of him is best attested from the Hurrian kingdom of Kizzuwatna, where he appears in various festivals related to Teshub of Šapinuwa.[11] He is also attested among the gods worshiped in Lawazantiya.[16]
In Emar, both Tašmišu and Tenu were worshiped as members of the entourage of Teshub.[17]
The first myth of the so-called "Kumarbi cycle" describes the birth of Tašmišu. Like his brother, he was born after Kumarbi bit off the genitals of Anu.[18]
In the Song of Ullikummi, Tašmišu joins his siblings Teshub and Šauška when they go to see eponymous stone giant after being warned by the sun god Šimige.[19] Later he reveals Teshub's fate after the initial confrontation with the monster to his wife Hebat.[20] He also suggests to his brother that to find a way to defeat the new adversary they need to meet with the god Ea in his dwelling, Abzu, in the Hurrian myth assumed to be a city rather than a body of water.[21] After Ea agrees to listen to them, Tašmišu shows his gratitude.[21]
