Boss Gallo was a Gungan warlord who resided on the planet of Naboo many millennia prior to the Imperial Era. During that time, Gungan tribes were in a perpetual state of war with one another; this continued until Gallo, employing both diplomacy and military might, gained control of the Gungan cities and unified them under his leadership.
Gallo assembled a sizable army with the intent to destroy the ancient fortress city of Spearhead. Spearhead served as the home of the rebellious Boss Rogoe and the remaining resistance against Gallo's unified Gungan forces. Following this, Gallo commissioned the construction of a fresh Gungan [capital](/article/capital], named Otoh Gunga, directly atop the ruins of Spearhead. The original foundations established by Gallo became known by the name of the Ancient Quarter.
The initial mention of Gallo in the new Star Wars canon occurred in Nexus of Power, a 2016 resource published by Fantasy Flight Games for the Star Wars: Force and Destiny roleplaying game. Within the Star Wars Legends timeline, Gallo was initially referenced within Star Wars: Galactic Battlegrounds: Prima's Official Strategy Guide by Steven L. Kent, which was released on November 7, 2001. Subsequently, Gallo appeared in the LucasArts video game Star Wars: Galactic Battlegrounds, launched on November 11 of that same year. Boss Gallo received a mention in the non-canonical 2022 video game LEGO Star Wars: The Skywalker Saga, wherein a Gungan character employed masculine pronouns when referring to Gallo.