From Nookipedia, the Animal Crossing wiki
Nat (カメヤマさん, Kameyama-san) is a chameleon who appears in Animal Crossing: City Folk and returns in Animal Crossing: New Leaf. He can be found hosting the Bug-Off event in the player's town. Like Chip, he speaks with a cranky villager's voice (deep, masculine). He has small spectacles that sit on the end of his nose, similar to the style of an explorer who searches for new creatures (such as insects, mammals etc.). He also wears explorer clothing, which goes with his explorer appearance, and he carries a blue net (similar, but not the same as the silver net) which cannot be obtained during the game and is an item unique to him. Nat's name could either be related to "net", which he uses, or "gnat", a type of bug. Unlike Chip, Nat does not eat the bugs, however, it is implied that he does, as he calls the bugs scrumptious and delectable, and he makes slurping noises after receiving an insect. Despite this, he denies this and says that he is keeping them for purely scientific reasons.
During the Bug-Off
He pitches his green and white tent outside the Town Hall similar to Chip, who runs the Fishing Tourney, at 9 a.m. and waits for players and villagers to bring him different types of bugs and rates them according to rarity, luster, color and size, and then gives them a mark using an unknown point system. For each insect players give him that is rated highly and breaks the first place record, players receive an item of furniture. Any insects given to him will not be returned, whether they win or not. He picks the winner at 6 p.m., giving a total of nine hours to find insects.
The winner with the highest rating insect wins a trophy, which is sent to him or her in the mail by Nat for the next day; a message written by him then appears on the bulletin board.
In Animal Crossing: New Leaf, he plays a similar role, but now presents an awards ceremony, hands out trophies to the top three competitors, gives furniture from the Insect Set for record-breaking entries scoring at least 80 points, and gives the player a golden net if they catch every type of bug.
In Animal Crossing: amiibo Festival, Nat comes during the warmer months to host the Bug Off. He will judge bugs brought to him by the player, and the winner is awarded 20 Happy Points.
Nat appears as a collectible trophy.
Happy Home Designer amiibo Card
Names in other languages