Doctor Nitrus Brio (Earth-6515)

"So, you're helping Cortex to gather the Chaos Emeralds, and yet you've acquired a Power Crystal! Interesting! Heheheheh! Well Sonic, heheheh, know this, as long as you are allied with C-C-C-Cortex, you are my sworn enemy and I will do everything in my power t-t-t-to stop you! Heheheheheh! If the fate of the world is truly your concern, you must g-g-gather the Crystals, not the E-E-E-Emeralds."

- Doctor Nitrus Brio

Doctor Nitrus Brio is an evil genius scientist who formerly worked under Doctor Neo Cortex as his right-hand-man during his debut on the first Sonic Hedgehog, but his loyalty has shifted through the series, with him working on his own according in Sonic Hedgehog 2, with Doctor Nefarious Tropy in Sonic Twinsanity, and once again with Cortex in Sonic: Mind Over Mutant. Much like Cortex, he specializes on mutating animals and possesses a mutagen liquid that transforms him into Titan Brio.