Folks who have watched the original Pokémon anime must have heard of the Squirtle Squad. Ashe’s own Squirtle was a member of this squad, a group of Squirtle's who go around causing mischief among other things.
Furthermore, the Squirtle Ash carries around wore an awesome looking pair of sunglasses while he was a member of the group. He was also its leader, so that should give you an idea of why he was always persistent in combat. In fact, all members of the squad wore sunglasses, but Ash’s Squirtle had a unique pair.
Now, with the trip down memory lane over and done, we’d like to point out that on Twitter, Pokémon GO possibly teased the Squirtle Squad. That’s basically our assessment from the Tweet and the accompanying image.
We’re not going to say outright that the Squirtle Squad is coming to the game, but you know what? Maybe the developer, Niantic, could introduce a costumed Squirtle with a sunglass to commemorate the squad.
Bear in mind that in the past, Niantic has released costumed Pokémon, so it should come as no surprise if a new one is released in the near or distant future.
So far, all costumed Pokémon came from the Pikachu family of creatures. It would make sense, then, for Niantic to do something with another family of Pokémon, and Squirtle is a perfect choice.
It should be noted that this is merely speculation on our part, but hey, anything is possible in the world of Pokémon GO, and we truly believe a costumed Squirtle is one of those possibilities going forward.