The unnamed Colombian Gang is a criminal group based in New Mexico and the eastern United States. Well armed and trained, they appear to be mercenaries, offering services to other criminal organizations such as the Juárez Cartel.
At some point, Mike Ehrmantraut had an encounter with members of the gang "back East." ("")
The gang ambushed Saul Goodman in the desert after he picked up Lalo's bail money from the Cousins. Before they could kill Saul, Mike intervened and eliminated the entire gang with his sniper rifle save for Tiburón, who was able to escape. Tiburón would meet his end a day later, however, after being lured by Saul, allowing Mike to snipe him. ("")
Mike later identifies them as a Colombian gang, based on the symbol the members had tattooed on their skin. After Mike draws the symbol for him, Gus quickly deduces that the gang was, in fact, hired by Juan Bolsa, in an attempt to protect Gus' interests and, by extension, the cartel's. Bolsa did this unaware of Gus' true plans. ("")
After Lalo's departure, Saul tells Kim Wexler the truth about what happened with the gang. ("")