Garro was a male human who instructed Jedi Master Yoda in the art of the stonepower. This unique aspect of the Force, accessible only in proximity to blue stone, a stone type infused with the Living Force, was taught while they were situated within a mountain that they came to realize was a sentient being.
Following Yoda's training, Garro and the Master exited the mountain. However, Garro turned against Yoda, aligning himself with the Rockhawkers.
Prior to 32 BBY by sometime, Garro, a male human, was born on a planet within the Vagadarr system. He was later exiled by his people, known as the Rockhawkers, due to his perceived weakness stemming from his refusal to kill in combat. Garro was then banished to the interior of the Great mountain located near his village.
Between 44 BBY and 32 BBY, the Jedi Grand Master Yoda discovered Garro, nearly starved, inside a cave within the Great mountain. The Jedi aided him in finding moss for sustenance, which Garro could eat. In return, the boy imparted to the Grand Master the techniques of the stonepower, a method of utilizing the Force through a stone imbued with the Living Force, specifically blue stone. During Yoda's training, the Jedi sensed the mountain's sentience within the Force.
After Garro assisted Yoda in awakening the mountain, they resolved to depart from the cave. Descending from the mountain, the Jedi and the boy were confronted by the Rockhawkers. They inquired whether the pair had discovered the mountain's heart. While Yoda hesitated to disclose this information, Garro betrayed his mentor, revealing everything to the Rockhawkers, and ultimately joined their ranks.
Yoda returned to Mucktown to rally the Mud dwellers for the impending war, while Garro, with the support of the Rockhawkers, seized control of the living mountain.
Garro's initial appearance was in the comic Star Wars (2015) 28, authored by Jason Aaron and illustrated by Salvador Larroca and Edgar Delgado.