B'Rat Ud was a V'radian chemist and savvy entrepreneur who lived in the Delphic Expanse.

Captain Jonathan Archer first encountered B'Rat at a deuterium station on Norellus, where Archer learned that B'Rat knew a formula for synthesizing trellium. Archer arranged to meet B'Rat at his shop on the Xanthan homeworld, where the Enterprise crew purchased the formula in exchange for spices from the ship's galley, including cayenne pepper, mustard seed, paprika, and pepper. He took great pleasure sniffing the "exotic" spices.

B'Rat's shop was located on Barge 12 of Tier 2 of the Xanthan floating bazaar. (ENT: "Rajiin")