Pokemon Sun & Moon — 01 September, 2016
The latest Nintendo Direct has just aired and it revealed a new Alolan form for Rattata. It is Dark/Normal type and has the ability Gluttony or Hustle. It's said that Yungoos was introduced to Alola to combat the Rattata population, but instead Rattata changed its type to scare off Yungoos.
It was also revealed that several Pokémon have their own unique Z-Moves. Two examples are Alolan Raichu which has Stoked Sparksurfer and Snorlax, which has Pulverizing Pancake.
The Direct also mentioned that a special Munchlax will be distributed from the launch of Sun/Moon, until January 11th 2017.
Update: a new video has been released:
Alolan Rattata as it appears in the Pokédex
Alolan Raichu using Stoked Sparksurfer
Snorlax using Pulverizing Pancake