Duumas was a Force-sensitive male individual who served the Jedi Order around the time of the Ruusan Reformation and attained the rank of Jedi Master. Around 1002 BBY, Duumas uncovered a prophecy foretelling the coming of a "Child of Light," a being with access to unlimited power in the Force. Following this revelation, Duumas sacrificed himself on the sparsely-populated planet Dalicron-4 in Outer Rim Territories, merging his spirit into a large and unusually-colored tree sited on a raised knoll to create a fifty-meter radius protective bubble surrounding the tree that was devoid of the Force.
Nearly one thousand years later, circa 2 BBY, the Human male Caeleb, the child heralded by Duumas, was born. Though unaware of the Jedi Master, Caeleb's father experienced a vision of Duumas' tree and Caeleb's parents settled in a homestead next to the tree with their son, the Force bubble created by Duumas shielding Caeleb from his Force power as the boy grew up.
Jedi Master Duumas was mentioned in Child of Light, a roleplaying adventure written by Lee Pickler and set within Star Wars Legends continuity that was published by RPGA in 2000 as the opening instalment of the Child of Light saga roleplaying trilogy. The adventure does not specify Duumas' species.