Pokémon: The Series Rewrite:Indigo League Part 1

episode 10: here comes the squirtle squad

Ash and the crew learn of crimes happening around Cerulean City to learn that it's because of a group called the Squirtle squad. This leads to them getting captured with Jesse, James and Meowth. They team up with Officer Jenny who decides to get the Squirtle squad for good. Squirtle decides to join Ash's team but being that he's the seventh team member for Ash, he's sent back to Professor Oak. Ash learns that you can only carry 6 Pokémon at a time. Ash decides to switch out his Clefairy with Squirtle.