He was voiced by Francisco Ramos.
Mauro also appeared as one of the antagonists in Angry Birds Rio.
Mauro is a light brown marmoset who has white hair and green eyes and wears a paper clip for a ponytail. In the junior novel, Mauro wears a coat stuffed with stolen valuables on it.
Mauro first appeared in the jungle scene to call in his marmosets after they stole several items from tourists without ever being caught. It was at that moment Nigel (being sent in by Marcel) asks Mauro and his gang to search for two rare blue Macaws (Blu and Jewel). Mauro demands to know what he and his gang will get in return, to which Nigel responded by flying his new "ally" Mauro into a great height and making him fall, forcing him to oblige to the deal in exchange for saving his life.
Mauro and the marmosets eventually track down the two birds to a bird dancing club, so he decides to take them hostage. However, the other birds engage into a fight against the marmosets and Mauro ends up being immobilized when Jewel uses her chain to smack him in the groin, allowing herself and Blue to escape. Upon hearing of this, an annoyed Nigel beats up Mauro before deciding to do the job himself.
During the credits following Nigel' defeat, (apparently) Mauro spotted Nigel (who's been plucked of his feathers after crashing into a plane propeller) and laughs at him while using a camera to take pictures as payback for the mistreatment Nigel gave to him and the marmosets earlier.
- Mauro's name was never mentioned in the film but he was listed in the credits as "Lead Marmoset". However, his name was revealed in the Rio videogame.
- In Angry Birds Rio, Mauro and the other marmosets are shown as Nigel's official henchmen. Mauro himself also appears as a boss. He is fought in the stages Carnival Upheavel and Market Mayhem, and is way stronger than the other marmosets, who normally take one hit to down, are.