A young Zeltron male with red skin was a part of the Jedi Order throughout the last decades that the Galactic Republic existed. This boy was a student learning at the Jedi Temple located on the planet of Coruscant, and he frequently practiced fighting with training weapons against another youngling, Caleb Dume. On one occasion, the Zeltron was present for a talk given by Jedi Master Obi-Wan Kenobi inside the Temple's central security station. During this lecture, Kenobi described the Jedi beacon to the younglings who were there, explaining that it was a signal capable of summoning all Jedi from throughout the galaxy back to Coruscant. Dume, who was also at the lecture, questioned Kenobi about the beacon repeatedly, and the Zeltron boy later made fun of him for this during their subsequent sparring match.
This unnamed youngling was initially introduced in A New Dawn, a book that John Jackson Miller wrote and that came out in 2014. The book did not specify the boy's species because Miller wanted to illustrate how diverse the Star Wars galaxy was by showing that characters don't always think about the species of the people they encounter. The author later put the book's production notes on his blog, and these notes disclosed that the boy was a Zeltron.