The Alangabi were a tribe of the Payav civilization native to the Ayanava Valley on planet Mestiko. The Alangabi were noted for the distinctive tattoos they wore, depicting twined blue and red thorned vines, drawn below their left ears.
The Alangabi had a centuries-old rivalry with the neighboring Nehdi tribe. In the mid-23rd century, the Alangabi begane developing bioweapons which targetted specific Nehdi genetic codes. These efforts were abandoned sometime prior to 2265, when "the Pulse" devastated much of the Ayanava Province. In 2293, the Alangabi's buried (and forgotten) toxins began to seep into the water supply and started killing Nehdi children. The Alangabi's complicity was uncovered by Doctor Leonard McCoy and Commander Nyota Uhura; these revelations forced the Alangabi and Nehdi to resolve their rivalry once and for all, with the Alangabi agreeing to clean up and destroy all traces of their pathogen. (TOS - Mere Anarchy eBook: Its Hour Come Round)