Doctor Nitrus Brio is the on-again off-again henchman of Doctor Neo Cortex. Not as pushy or driven as his boss, Brio is the one who developed the mutagenetic techniques still used by Cortex today, but his initially low sense of self-esteem allowed Cortex to take the credit. The tension that resulted from this eventually led Brio to temporarily leave Cortex, at one point even destroying Cortex's space station and mass mind-control device in Cortex Strikes Back out of spite along with the need to prevent Earth's destruction.
Brio would later reconcile with Cortex in Crash: Mind over Mutant, though his bitterness over Cortex's past betrayal has driven him to obsessively claim ownership of whatever he claims to have invented (and things he probably didn't invent). Brio often used chemicals mixed by himself, which he would consume to increase him own power level; he would develop an addiction to these mutagens by Mind over Mutant.
In the first Crash Bandicoot and Cortex Strikes Back, Brio is voiced by Brendan O'Brien, who voiced a handful of other characters in the series.
In Crash: Mind over Mutant, his voice is provided by voice actor Maurice LaMarche.