Walkappa resembles a short, light-blue colored Kappa with a wide oval head, with equally wide lips. The top of his head is round and shiny, girded by grass-colored hair. He carries a small water bottle which is red in color.
In Yo-kai Watch 2, certain Yo-kai have a Rare variant, which gives a Yo-kai that is largely supporting one faction over another, except for a select few. In this case, Rare Walkappa are affiliated with Fleshy Souls, and can be seen with a water bottle that is red with white polka dots.
In the anime, Walkappa is kind and brave. However, he does seem a little awkward. In the English dub of the anime, Walkappa speaks with a surfer accent. Walkappa's favorite food is pizza (in the English; sushi in the original version), he claims that kappas favoring cucumbers is a stereotype（in the original version, Walkappa claims he favors sushi lately over cucumbers).
Walkappa has a rivalry with Faux Kappa. In EP033 of the anime, they had a duel to see who was the most genuine kappa between the two of them. After Walkappa won by wearing sunscreen on his dish, he earned Faux Kappa's respect as a fellow kappa. At first, Walkappa was a bit intimidated by Faux Kappa, but he looks up to him now. The kappa rivalry ends in EP097.
In EP097 of the anime, it is revealed that Walkappa has paired up with Kapper to form a rap group. By the end of the episode, it's shown that even the classic yo-kai Kappa is drawn in by rap music. The three kappas then form the music group "Mizukakitai" and have their first performance in Nate's house.
In The One In The WaterNate is investigating strange sightings near a river which he believes is a Yo-kai. Whisper then explains that people were most likely seeing a kappa, and that they were pretty famous Yo-kai. As Nathan scans the river, he finds a chipped bowl which he and Whisper mistake for a kappa. Meanwhile, Walkappa appears behind them and tries to get their attention. Then, a delivery boy comes and finds the bowl, but he trips when he goes to return to his bike and the bowl lands on his head. They all laugh Nate calls him a kappa, but they never realize that Walkappa was there the whole time.
Later, in the same episode, Nathan is having trouble with Tattletell. Nathan thinks he ran out of medals (thanks to Jibanyan failing and Happierre ignoring the summoning for vacation with Dismarelda), but then he discovers Walkappa's and calls him out. Tattletell tries to possess him, but it turns out Walkappa doesn't have any real/dirty secrets, so she tires herself out trying to force out his dirty secrets and loses.
In Which One Is Real?, Nate sought out Walkappa in order to do a report on the kappa when they get visited by Faux Kappa. They had a duel to see who was the most genuine kappa between the two of them. After Walkappa won by wearing sunscreen on his dish, he earned Faux Kappa's respect as a fellow kappa. When watching Nate do his report on him, Walkappa was not pleased that the other students mocked Nate and his report.
In Yo-kai Chansin, he and Manjimutt were summoned because of how unlucky they are. However when they played the sushi roulette, Chansin instead gets burned by the wasabi sushi.
In EP097, he becomes a DJ so that he can form a music group with Kapper. Nate summons Faux Kappa on the two of them, but it is revealed that even the Classic Yo-kai likes rap music. The kappa rivalry ends and the three of them become "Mizukakitai."
In EP130, he wins the Yo-kai Watch Dream and trades it with the disfigured Whisper.
Upon listening Bear's story of how he lost a ring in Catfish Pond, Nate goes looking for a kappa to help Bear out. Along the bank of the west canal, Nate meets Walkappa in the disguise of a sunflower, and weak from hunger. Walkappa agrees to help Nate out in exchange for three carp for lunch, though Nate has no fishing rod, then Walkappa remedies that problem by giving him one to catch the fish.
As promised, Nate brings Walkappa the three carp who wolfs them down and thanks Nate by giving him his Yo-kai Medal. Later Nate talks to Bear at Catfish Pond, who is still looking for his mom's ring, and summons Walkappa to help look for the ring, who makes a big show of splashing around the pond for the ring. Walkappa finds the ring, but all the splashing and water acrobatics drew the ire of Catfish Pond's boss, SV Snaggerjag, and attacks Nate. After the fight, Walkappa apologizes for his wild swimming, then gives Nate the Special Ring Bear was looking for.
During the events of Request: Walkappa's Bottle, occuring sometime after the Lost Ring incident, Walkappa had lost his bottle and tasks Nate & Whisper in finding it along the west canal, though all they found was trash. They eventually find the bottle at Catfish Pond after grilling some more info from the kappa Yo-kai.
Walkappa appears in the Western and Eastern River banks in Uptown Springdale.
Loafing: "I love cucumbers..."
"Nogappa" is a combination of nogamo (Japanese: 野鴨,"wild duck") and kappa. "Walkappa" is a portmanteau of walking and kappa.
As the name implies, Walkappa (as well as his evolution, and Faux Kappa) is based on the famous water creature called the kappa (Japanese: 河童,kappa lit. "river child"), one of the most commonly known youkai species. Physically, they're green-skinned, child-sized beings with webbed feet and the beak and shell of a turtle. On top of their heads there's a bald spot with a small cavity filled with water: it's the source of their strength, and if it's spilled or poured out they'll grow weak and eventually dry up, for which reason they rarely leave the rivers they inhabit.
They're excellent swimmers, can stretch out their arms, and their favourite things are cucumbers and playing shogi. They also enjoy sumo wrestling, and will sometimes challenge humans to a match, only to use illusions to trick them into grappling with the air or some inanimate object. Though they normally only engage in this kind of pranks, some can actually be dangerous, and will even drown people swimming in their rivers or suck out their soul through their rear end.
Most of the time, however, kappa are regarded as harmless or even friendly and beneficial. They'll always honor a debt, and are knowledgeable about medicines and fixing broken bones, and are polite to a fault, where more than one tale depicting the protagonists foiling kappas by bowing to them, making them bow back and spill their water. In Tokyo, they are the symbol of Kappabashi-dori, the city's kitchen utensil district. Sushi rolls with cucumber instead of tuna are called kappamaki in their name.
In the English dub, his love for pizza and his stereotypical surfer accent could be a reference to the Teenage Mutant Ninja Turtles series, specifically the character Michelangelo.