Pokémon Ultra Sun and Ultra Moon/Version Differences

There are a lot of differences in Pokemon between Pokemon Ultra Sun and Ultra Moon.

Minor Differences

 * On Illima's Trial, you'll have to fight Totem in Sun and Totem Alolan  in Moon.
 * Sun and Moon are set 12 hours apart, so Sun follows the system clock, whereas Moon's in-game time is transposed 12 hours from the system clock. For instance, if it is 10AM on the system time, the in-game time in Sun will be 10AM, but in Moon it is 10PM.

Solgaleo
is the legendary Pokemon exclusive to Sun version, featured on the box art. Known as the Sunne Pokémon, it's a Psychic/Steel type, making it vulnerable to only 8 types: Fighting, Bug, Water, and Electric (1x), Ground, Ghost, Fire, and Dark (2x). Solgaleo is immune to poison and is resistant to: Normal, Flying, Rock, Steel, Grass, Psychic, Ice, Dragon, and Fairy (1/2x). After summoning Solgaleo, it'll be merged with Necrozma, and you'll be forced to battle it and faint it. Before heading up to battle the Elite Four, if you go to Mahalo Trail, you'll be able battle and catch Solgaleo. When caught, Solgaleo will be level 60. It'll know the moves Cosmic Power, Crunch, Zen Headbutt, and Sunsteel Strike, its signature move. Sunsteel Strike lets it turn into a phase known as Radiant Sun to perform the attack. Radiant Sun changes its color scheme to white and gold, and it glows. It jumps up, summons a giant fire beam that resembles the sun, and charges through the ray to attack its opponent.

Finding Solgaleo is only in the Ultra Sun version, so if you're an Ultra Moon player you must trade in order to receive it.

Passimian
is an Alolan Pokemon exclusive to Ultra Sun version.

Turtonator
is an Alolan Pokemon exclusive to Ultra Sun version.

Alolan Vulpix
is a Kanto Pokemon that has an Alolan Form. It evolves into Alolan Ninetails and is exclusive to Ultra Sun version.

Alolan Ninetails
is a Kanto Pokemon that has an Alolan form. It evolves from Alolan Vulpix and is exclusive to Ultra Sun Version.

Buzzwole
(also known as UB-02 Absorption) is an Ultra Beast exclusive to Ultra Sun version.

Kartana
(also known as UB-04 Blade) is an Ultra Beast exclusive to Ultra Sun version.

Cranidos
is a fossil Pokemon exclusive to Ultra Sun version. It evolves into Rampardos.

Rampardos
is a fossil Pokemon exclusive to Ultra Sun version. It evolves from Cranidos.

Tirtouga
is a fossil Pokemon exclusive to Ultra Sun version. It evolves into Carracosta.

Carracosta
is a fossil Pokemon exclusive to Ultra Sun version. It evolves from Tirtouga.

Cottonee
is a Pokemon exclusive to Ultra Sun version. It evolves into Whimsicott.

Whimsicott
is a Pokemon exclusive to Ultra Sun version. It evolves from Cottonee.

Rufflet
is a Pokemon exclusive to Ultra Sun version. It evolves into Braviary.

Braviary
is a Pokemon exclusive to Ultra Sun version. It evolves from Rufflet.

Groudon
is a legendary Pokemon exclusive to Ultra Sun version.

Omanyte
is a Pokemon exclusive to Ultra Sun version.

Omastar
is a Pokemon exclusive to Ultra Sun version. It evolves from Omanyte

Ho-Oh
is a legendary Pokemon exclusive to Ultra Sun version.

Blacephalon
(also known as UB-02 Burst) is an Ultra Beast exclusive to Ultra Sun version.

'Rockruff can only evolve into Lycanroc Midday Form in Ultra Sun, and Lycanroc Midnight Form in Ultra Moon. However, both evolutions are catchable in the wild.'

Lunala
is the legendary Pokemon exclusive to Ultra Moon version, featured on the box art. Known as the Moone Pokémon, it's a Psychic/Ghost type, making it vulnerable to 12 types: Flying, Ground, Rock, Bug, Steel (1x), Fire, Water, Grass, Electric, Ice, Dragon, Fairy, Ghost (4x) and Dark (4x). Lunala is immune to Normal and Fighting and is resistant to: Posion (1/2x), and Psychic (1/2x). After summoning Lunala, it'll be merged with Necrozma, and you'll be forced to battle it and faint it. Before heading up to battle the Elite Four, if you go to Mahalo Trail, you'll be able battle and catch Lunala. When caught, Lunala will be level 60. It'll know the moves Night Daze, Cosmic Power, Moonblast, and Moongeist Beam, its signature move. Moongeist Beam lets it turn into a phase known as Full Moon to perform the attack. Full Moon changes its color scheme to light blue and gold, and it glows. It flies up, opens it's third eye, and shoots a giant beam at the target.

Finding Lunala is only in the Ultra Moon version, so if you're an Ultra Sun player you must trade in order to receive it.

Oranguru
is a Pokemon exclusive to Ultra Moon version.

Drampa
is a Pokemon exclusive to Ultra Moon version.

Pheromosa
(also known as UB-02 Beauty) is an Ultra Beast exclusive to Ultra Moon version.