Ash goes to Seafoam Island to help Professor Oak to discover the mystery of how Slowpoke evolves into Slowbro. There, Professor Westwood V is also trying to solve the mystery. Jessie captures Shellder, and tries to rush a Slowpoke's evolution, forcing Psyduck to stall the evolution.
| Creator | N/A |
|---|---|
| Actor | Rica Matsumoto, Ikue Otani, Daiki Yamashita |
| Country | Japan |
| Production | Shogakukan Production |