Dent's Yanappu, a Grass-type Pokémon, travels alongside Dent in the Unova region. It features in the Pikachu short "Eevee & Friends," accompanying Pikachu, Oshawott, and Axew. During their adventure, the group follows a mysterious voice and encounters Sylveon, who guides them to the Eevee House. There, Yanappu joins playful activities with the resident Eeveelutions, including a game of tag indoors with Eevee and Jolteon.
Yanappu proves its loyalty and combat readiness during a forest encounter. When Brock is abducted by a wild Hatterene causing hallucinations, Yanappu battles Brock's Steelix under Dent's command, showcasing its role as a reliable battle partner.
At the Eevee House, Yanappu joins celebrations and watches a talent show featuring performances by Meowth and Wobbuffet, though it does not take the stage itself. Later, it witnesses Umbreon and allies creating a cosmic light display for the group. Yanappu remains Dent's constant companion, regularly appearing alongside him in group settings and battles, with no significant individual development documented in the available materials.