Nate is the first character you see and talk to on Big Nate Island. He tags along as you search for the lost time capsule and is also the one to give you the peanut butter crackers after winning the "Go To Jail" game on the playground. He races you to the map on the jet skis as well.
He is the main character in the Big Nate comics by Lincoln Pierce.
Big Nate is the only character to follow a Poptropican around throughout an entire island.