Evolutions are an essential part of Pokémon, but some of the best Pokémon of all time have no evolutions at all.

Morpeko and a slew of coveted costumed Pokemon are coming to “Pokemon Go” for the first part of the Halloween event. Beginning at 10 a.m. Oct. 22 and going on to 10 a.m. Oct. 28, players will have a ...