Nefasto (interpreted by Ernani Moraes) is an evil bacterium created by Arielibã (an ancient scientist of the island "Rá-Tim-Bum") in an experiment; but, Nefasto rebelled against Arielibã, and mixed with his body, so, his body gets a sickthat became a mixture of bacterium and human, and we were possessed by Nefasto, and Arielibã is killed, but his soul still exists.
Nefasto wants domains the human world, but for this, needs to understand them, so, he uses the magic staff of Arielibã to bring five teenagers to his island, where he will spies their acts (with "Guarana's cameras", that is cameras disguised as Guarana's fruits), to understand them. So, he feigns be Arielibã.
A witch (she is from an ancient race of wizards: theguievenermuquese) named Hipácia is an old habitant of the island, and with a potion named Moftaa Shabaab, lived during 8000 years, and in some moment in her life, she lived in Alexandria and escapedfrom there, and on the island, worked with Arielibã on experiments toimprove the world, but in one of these experiments was Nefasto, that killed Arielibã and made her sad; how Nefasto knew about Hipácia, tries to use the Moftaa Shabaab to get immortality, because the life of a bacterium in a human body is too short.
He tries to catch the Hammer of Volcano in the movie to conquest the world.
After, he was killed when Propolis was injected in Arielibã body, and Arielibã die soon after.
His name means "Nefarious".
Nefasto is a bad guy, and is evil so much; he is not an evil genius, but a bit smarty, and think he is most smarty than his henchmen. He is very crusty.
Nefasto is like a wizard, because he uses the staff of Arielibã. Him as a bacterium, can possess the body of the victim and make him sick.