The owner of the Banana Slakoth Garden, Marcel was in the middle of a big problem when Ash and his friends showed up. The Garden had been closed due to a Snorlax eating all of the bananas in the park. To make matters worse, whenever any Pokémon tried to battle with the Snorlax, it would use Yawn and make them fall asleep.

Marcel was just about to give up when Brock suggested that he capture a Slakoth from the Garden and evolve it into a Vigoroth. His reasoning was because of Vigoroth's Vital Spirit ability. This would prevent it from falling asleep.

Taking his advice, Marcel captured a Slakoth, and, after battling Ash's Pikachu, Torkoal and Grovyle, it evolved. Using the Wild Monkey Pokémon, Marcel battled the Snorlax and successfully captured it.

After opening the park, Marcel revealed that Snorlax had given him an idea. One of the rooms was designed for visitors to sleep if they were feeling tired, and Marcel's newly captured Snorlax helped them fall asleep using Yawn.

Ash and the others bid farewell to Marcel and continued to Lilycove City.