The Amacarra were a tribe that resided in the Amazonian jungle.
An Amacarra makes a brief appearance when they are acknowledged by Jaime on the Electroclan's journey to the Puerto Maldonado Starxource compound. After Michael escapes, he is taken in and healed by the tribe.
After introducing him to Tessa, a glow that had been staying with the tribe, the Amacarra release Tessa and Michael to the custody of The Voice. They are then completely obliterated by the Peruvian army for harboring the Electroclan, whom they considered to be terrorists.