From Bulbapedia, the community-driven Pokémon encyclopedia.
Nathaniel (Japanese: ナユタ Nayuta) is a character of the day who appeared in Strategy Begins At Home!. He is a small boy who lives in Twinleaf Town.
Ash met Nathaniel after spotting him peering from some bushes, and the two soon struck up a conversation. Ash allowed the budding Trainer to hold Pikachu after he asked politely. Nathaniel's enthusiasm and daily adventures reminded Ash of his younger self.
Nathaniel's favorite type of Pokémon are Bug-types, and he hopes to catch many of them once he becomes a Trainer. The pair watched as a wild Heracross became attracted to some Honey that Nathaniel had earlier slathered on a tree. This encounter spurred Ash to tell him about his own Heracross.