A Chinese rumor about Pokémon Sun & Moon has seemingly gained credibility after predicting a Poison/Fire-type Pokémon which was fulfilled with the reveal of Salandit. You can read it below, translated by Cresselia~~ of Smogon Forums.
There will be no traditional Gyms and no Pokémon League in Alola. Your goal is to actually create one. After you do, an Elite 4 will appear which are the leaders of each island
The final starter evolutions will be an Archer, a Wrestler and a Siren
The diamond stones will be collectible throughout the region and act similarly to Mega Stones but not exactly
New Pokémon based on a dolphin, sea cucumber, snowman, mushroom and a rugby monkey are there
Rockruff’s evolution is a Werewolf
Mashadow, another copyrighted Pokémon name, has a very unique type combo
In addition, it seems that the majority of the images of the “leaked” starters (seen above) have mysteriously disappeared from Google image search. There is no way of knowing but it is possible official takedown notices have been sent to have them removed from search results. This is a warning: I may soon remove the images myself.