There are four main islands in Pokémon Sun and Moon, each one having their respective Guardian:
Litten is one of the newest Pokémon that has been introduced as part of the new 7th Generation games; Pokémon Sun and Pokémon Moon, Litten is one of the three Starter Pokemon that you can pick from while in the Alola region, Litten is a cat-like Pokemon that has been classified as the Fire Cat Pokemon, it has the Fire-typing, its height is one foot and four inches, it weighs 9.5 pounds, it has the typical Fire-type Starter Pokemon which is the Blaze ability and it will also know the Ember attack once you select it as your Starter.
Popplio is one of the newest Pokémon that has been introduced as part of the new 7th Generation games; Pokémon Sun and Pokémon Moon, Popplio is one of the three Starter Pokemon that can be selected in Sun and Moon and it was also classified as the Sea Lion Pokemon, it is a Water-type, its height is one foot and 04 inches, it weighs 16.5 pounds, it has the typical ability for Water-type Starter Pokemon which is Torrent and it will also know the Water Gun attack once it becomes your partner.
Rowlet is one of the newest Pokémon that has been introduced as part of the new 7th Generation games; Pokémon Sun and Pokémon Moon, Rowlet is one of the Starter Pokemon in Alola and it has been classified as the Grass Quill Pokemon, it is of the Grass and Flying-type, its height is exactly one foot, it weighs 3.3 pounds and it has the usual normal ability for Grass-type Starter Pokemon which is Overgrow and it will start with the attack called Leafage.
Wishiwashi is a Water type, and it was introduced in the Generation 7 games, Pokemon Sun and Pokemon Moon.
Wishiwashi has two forms:
Litten evolves into Torracat starting at level 17 and later into Incineroar at level 34.
Rowlet evolves into Dartrix starting at level 17 and then into Decidueye at level 34.
Poplio evolves into Brionne starting at level 17 and finally into Primarina at level 34.
Solgaleo is a Psychic-Steel type, and it was introduced in the Generation 7 games, Pokemon Sun and Pokemon Moon.
Solgaleo is a Legendary Pokemon, and the game mascot of Pokemon Sun.
Comfey is a Fairy type, and it was introduced in the Generation 7 games, Pokemon Sun and Pokemon Moon.
Minior is a Rock-Flying type, and it was introduced in the Generation 7 games, Pokemon Sun and Pokemon Moon.
Minior has two forms during battle:
Oranguru is a Normal-Psychic type, and it was introduced in the Generation 7 games, Pokemon Sun and Pokemon Moon.
Cosmog is a Psychic type, and it was introduced in the Generation 7 games, Pokemon Sun and Pokemon Moon.
Tapu Koko is an Electric-Fairy type, and it was introduced in the Generation 7 games, Pokemon Sun and Pokemon Moon.
Tapu Koko is the guardian deity of Melemele Island.
Tapu Lele is a Psychic-Fairy type, and it was introduced in the Generation 7 games, Pokemon Sun and Pokemon Moon.
Tapu Lele is the guardian deity of Akala Island.
Tapu Bulu is a Grass-Fairy type, and it was introduced in the Generation 7 games, Pokemon Sun and Pokemon Moon.
Tapu Bulu is the guardian deity of Ula'ula Island.
Tapu Fini is a Water-Fairy type, and it was introduced in the Generation 7 games, Pokemon Sun and Pokemon Moon.
Tapu Fini is the guardian deity of Poni Island.
Lunala is a Psychic-Ghost type, and it was introduced in the Generation 7 games, Pokemon Sun and Pokemon Moon.
Lunala is a Legendary Pokemon, and the game mascot of Pokemon Moon.
Magearna is a Steel-Fairy type, and it was introduced in the Generation 7 games, Pokemon Sun and Pokemon Moon.
Magearna is a Mythical Pokemon.
The male generic name is Sun and the female is Moon
Squirtle cannot be caught or found in Pokemon Sun or Moon instead you will need to wait until Pokemon Bank is updated in January of 2017 so that you can transfer Pokemon from previous games over.