"So, let's use the time we have! I want to do something good before I have to wear those dorky outfits again!" -- Numbuh 0.1/BruceBruce (previously known as Numbuh 0.1) is a blond boy and a part of the Delightful Children From Down The Lane.
Like the rest of the Delightful Children, Bruce is most commonly seen wearing a blue school uniform with a gray badge, knee-high socks of the same color, and brown shoes, on top of a white dress shirt and red tie. He also has blond hair.
It is revealed in Operation: Z.E.R.O. that the Delightful Children are the operatives of the legendary "lost sector" of the KND, Sector Z, with Bruce as Numbuh 0.1. Along with the rest of the sector, he was captured by Father and placed in the prototype Delightfulization Chamber, which had much stronger effects than intended, Eleventy Billion-fold in fact, and completely destroyed the children's individual identities, creating the hive mind, that is the DCFDTL and destroying the unstable machine.
See Delightful Children from Down the Lane's ultimate fate.