Snowy, when hatched, is a very curious and naive Pokémon due to her young age, but she also started off as a bit shy around others, and even gave Ash her version of a cold shoulder when he tried to pet her by freezing him with its Powder Snow to keep everyone away from her. Snowy took an instant liking to Lillie, due to seeing her as a parental figure because she took good care of it as an egg. As they spent most of the day bonding on the day she hatched they began to form a strong partnership and friendship. Much like Serena's Sylveon, as a Eevee, was comfortable with Clemont's Bunnelby and their friendship, Snowy felt comfortable and is best friends with Ash's Torracat, due to also not being entirely too hyperactive and energetic as Lillie and Snowy herself.
She also shows great bravery when trying to protect Lillie from Team Rocket. Initially, Snowy didn't want to play with her trainer friends Pokémon or be friends with them either at first but eventually warmed up to them in the end. Snowy also had trouble opening up to other people, but began to warm up slowly after staying with Ash and his Pokémon temporarily.
Snowy can also be naughty at times, such as freezing Lillie to show her affection.
Despite her confidence, Snowy is shown to be uncertain about evolving when Lillie sees that Snowy isn't ready to evolve yet when she shows her the ice stone and Lillie keeps until she is ready.
As an egg
Snowy, as an egg, was found by Principal Oak near Mount Lanakila. She was compared to a regular Vulpix egg brought to Alola from the Kanto region by Ash Ketchum. Oak took care of the Kanto Vulpix egg, and left the Alolan Vulpix egg in care of Lillie and the other students. Lillie decided to take the egg home to try and get over her fear of touching Pokémon, and after a wild Salandit tried to eat the egg, she managed to face her fear and held the egg to protect her.
Ever since then Lillie has been taking good care of the egg and fearing for her safety. The egg was later watched by Professor Kukui who was telling her to hurry up and hatch so she could play with the other Pokémon.
Later, the egg was in Lillie's care while the others competed in the race. During the race, she began to notice that the egg starting to glow. Mallow proposed Lillie should enter the race with her, after it hatches. The next day, the egg started to hatch. To everyone's discovery, Lillie named the egg "Snowy" while she was taking care of her. The egg soon began to crack.
The egg hatched into a white Alolan Vulpix. After the egg hatched, the egg that Ash brought from Kanto hatched into a red Vulpix. Snowy used Powder Snow on Ash and Rotom, after Ash spooked her when he tried to pet her. Samson's Vulpix, however, helped Snowy become friends with the other Pokémon. Principal Oak told the students they could raise the Alolan Vulpix while he raised the Kanto Vulpix. Ash and everyone agreed that Lillie should be its trainer, since she been taking care of her this whole time and had a nickname for her. Professor Kukui gave a Poké Ball for Lillie to catch Snowy in, but she missed and hit Ash before hitting the ground. Out of curiosity, Snowy touched the button and went into the Poké Ball and jumped right in with everyone seeing that Snowy chose Lillie to be her trainer on her own. Lillie let Snowy come out of its Poké Ball, then she tried touching her. However, she was unable to do it, much to Snowy's sadness. After everyone left, Lillie decided to walk home, so she could bond with her first Pokémon. While walking Lillie told Snowy that she doesn't know why she couldn't touch her or other Pokémon, but she told Snowy that wanted to do something about it because she deeply cares about her a lot making Snowy very happy. Lillie took Snowy to a malasada donut shop to try some malasada donuts, which she liked a lot. While continuing the walk they were then ambushed by Team Rocket, who wanted to steal Snowy. Due to Lillie's quick thinking and Snowy's Powder Snow, they were able to get away before hitting a dead end. Team Rocket caught up to them; Snowy did the best she could to protect Lillie, but she got hit by James' Mareanie's Sludge Bomb as she went over the building then Lillie jumped after her, without a second thought, to protect her partner and friend. Lucky for them Ash's Rowlet was able to catch them in time using its Leafage attack to save them. Landing safely with Mallow catching her and happy that her Pokémon was okay, Snowy froze Team Rocket with Powder Snow. Out of nowhere, Bewear showed up and took them away again. Ash and Mallow were happy Lillie could touch her own Pokémon which made both of them delighted. The following day, everyone was glad that Lillie could hold Snowy with no problem. Lillie told Snowy that the other Pokémon are her friends. Snowy greeted everyone by jumping with joy with the other Pokémon, then her jumped back to Lillie's arms. This encouraged Lillie to touch other Pokémon without fear one day.
Snowy was seen playing happily in a bubble made by Popplio. Then Lillie tried to help Ash to distract Kiawe by telling Snowy to imagine it played with Rockruff a while ago. Snowy helped Lillie and her classmates rescue Ash and Litten from an angry Palossand by freezing it with Powder Snow, while Ash's Pikachu and Lana's Popplio searched for its missing shovel. Snowy was unable to freeze it, but Lillie and her friends started blowing a wind. This helped Snowy, who managed to freeze Palossand. Yet, it soon grew exhausted, though Lillie hugged it gratefully. Snowy was then seen playing with its Pokémon friends with Charjabug at the front. Hearing Gladion was in town, Lillie sought him out. She showed that she could touch Snowy; Gladion bluntly replied she should take care of her. Since Gladion didn't want to return to the mansion, he left Lillie and Snowy.
Snowy played baseball, being on Kiawe's team as the Left Fielder. She helped Lillie to catch the ball and she was praised by her, who was thankful. During camping, Snowy playfully froze the pot of curry that Lillie was cooking, which caused Litten, who was the one to light up the fire, became extremely outraged. Later, Snowy's energy was drained by a Morelull. Even after Snowy was fed, the Morelull appeared once more and put everyone to sleep, then drained more of their energy. However, Ash started eating the curry and let Morelull drain his energy to power it up. After Morelull was fed, the group followed Morelull, who joined the others of its kind to a giant tree. There, everyone watched as the Morelull evolved into Shiinotic. The Shiinotic Ash befriended came, thanking for taking the energy, then put the group to sleep. The next day, the group, including Snowy, woke up, and they didn't feel hungry, as the Shiinotic returned the energy it borrowed.
Before the class started, Snowy watched other Pokémon having a race around the room, that Pikachu won. Since Kukui had the class take a task to exchange Pokémon, Ash traded Pikachu for Lillie's Snowy. Snowy was saddened to be separated from Lillie, who went away with Pikachu. At Kukui's house, Ash tried to befriend Snowy by sending his Pokémon out. However, Snowy refused to eat, making Ash saddened and Rotom confused, as that was supposed to be her favorite food. Instead, Snowy went sleeping next to Litten. The next day, Ash noted Snowy had not eaten anything and proposed to go for a walk. Snowy became happy, and Ash ran off to the marketplace lady. There, Snowy saw how Ash's Pokémon were eating and Litten gave her a piece of fruit. Snowy started eating and liked the food, while Ash was thrilled he was getting to Snowy. The group came to the beach for training, where Ash told Snowy she could surprise Lillie by becoming stronger. Snowy agreed, and used Powder Snow to freeze a wave, which amazed Ash. The following day, before the class returned their Pokémon back, Ash proposed a battle with Lillie. Lillie agreed, and had Pikachu battle Ash and Snowy.
Olivia, who came to the Pokémon School, wanted to meet the heroes' Pokémon, and met Lillie's Snowy. Since the task was to mount on Stoutland and find treasures, Lillie was unable to do the former. With Kukui and Olivia's encouragement, Lillie noted how she did befriend Snowy and Pikachu, motivating her to go atop Stoutland, a task she succeeded in. At Kiawe's farm, Snowy was eating the Pokémon food mixed with the Moo Moo milk, and liked that food, which fascinated Lillie as a result.
Snowy and Pikachu helped the kids to search for Mallow after she ran away from home.
When the three boys were discussing about the Charjabug car race, their enthusiasm made the environment in the classroom too hot, so Snowy decided to help by freezing them.
When Ash and his Alolan friends went to Kanto, Snowy became ill after departing from the airplane, worrying Lillie. Brock came and offered to perform a checkup on Snowy, and upon doing so, deduced that she was suffering from motion sickness during the flight, and that she would recover quickly. During the visit to Prof. Oak's lab, Snowy encountered a Kantonian Ninetales, which befriended it. When a Jigglypuff emerged from the destroyed Meowth robot, Snowy slept upon hearing it sing, and had its face doodled on as a result. 
Snowy had a sleepover with the class at Kukui's house. Unfortunately, Lillie regressed after seeing Type: Null and made Snowy puzzled as she was unable to touch her again.That night, Lillie even apologized to Snowy because she saw how eager her hoped to get hugged. The next day, Lillie wanted to hug Snowy but she was still unable to do so, causing Snowy to become more confused. After Ash and Lillie were being teleported to several places by Nebby, Snowy, along with Pikachu, Ash and Nebby were attacked by Faba at the Aether Foundation secret labs by Psychic attack of Faba's Hypno. As Lillie finally overcame her fear after thanking Silvally, Snowy jumped up to Lillie's arms to give her best friend a hug, as she can touch her partner again, with Nebby and Pikachu coming as well, as she can also touch them too.
Snowy, along with Umbreon and Silvally, attempted to protect Lillie from getting attacked by Nihilego. But she watched in horror as Nihilego abducts her mother, Lusamine, and carries her into the Ultra Wormhole Faba opened.The next day, when Lillie and Gladion faced Totem Kommo-o, Snowy was sent out to fight along with Silvally and it helped to freeze the ground so that Gladion could retrieve the Fairy Disc. When a large boulder which fell from the top nearly hit Lillie and Snowy during their escape with Gladion and Silvally, they were rescued by Pikachu thanks to his Electro Ball.
Snowy, along with all of the gang's Pokémon, witnessed the Tapu Guardians perform and ritual and Nebby's evolution into Solgaleo. After travelling through the Ultra Wormhole, the group finds Lusamine fused with Nihilego. As the group chases after her, Snowy, with the help from Ash's Lycanroc, helps Lillie get through to Lusamine's Clefable and snaps it out of the Ultra Beast's mind-control. Snowy then witnesses Lillie talking some sense into her mother as well as Ash and Pikachu performing the 10,000,000 Volt Thunderbolt Z-Move as a final ditch effort to save her. After saving Lusamine, Snowy and the rest of the gang leaves Ultra Space and returns to the Pokémon world.
Snowy later attended Professor Kukui and Professor Burnet's wedding ceremony.
Sometime later, Snowy helped Lillie and her classmates complete several Ultra Guardian missions and helped Ultra Beasts return home.And in the process it meets a new friend who is also an Ultra Beast, Ash's Poipole.
Snowy later travelled with Lillie to Mount Lanakila, where it was founded by Samson Oak. Upon arriving there, Snowy sensed the presence of an Alolan Nintales. Once they found it, they meet up with Ninetales' trainer, Cerah. Cerah tells Lillie that she and Ninetales are preparing for the Pokémon Sled Jump Games and after giving a magnificent demonstration, Lillie decided to compete in the games with Snowy as well as learning Aurora Veil. After a few hours of intense training, Snowy manages to perfect the Aurora Veil move and makes a spectacular jump in the competition. But despite that, they weren't able to win, which Lillie doesn't seem to care.
Later, Snowy, Lillie, Mallow, and Sophocles got separated from the Kiawe and Ash during another trip to Mount Lanakila. The group found themselves in a cave full of Alolan Sandshrew led by one bigger than a normal one. They soon discover that the cave is being invaded by a rogue Tyranitar who is trying to take over the territory. Snowy and Lillie decides to step in and help the Sandshrew defeat Tyranitar. Using the same strategy Olivia used in Ash's Akala Grand Trial, Snowy powers up Sandshrew with its Aurora Veil and attacks Tyranitar with a Powder Snow and Metal Claw combination. Snowy and Sandshrew emerge victorious and sent Tyranitar packing. Snowy then witness Sandshrew evolving into Sandslash with the Ice Stone Sophocles found and felt speechless about it. Sandslash gives Snowy and Lillie an Icium Z as a gift for their help. Upon reuniting with Ash and Kiawe, Sophocles gives Lillie the Ice Stone his Charjabug found. Lillie then attempts to evolve Snowy, but it got scared and backs away from the stone. Lillie then decides to hold on to the Ice Stone in case of Snowy changes its mind.
|Powder Snow||Getting to Know You!|
|Hail||Getting a Jump on the Competition!|
|Aurora Veil||Getting a Jump on the Competition!|
|+ indicates this Pokémon used this move recently.*|
- indicates this Pokémon normally can't use this move.
- Snowy is the first Alolan Form Pokémon owned by a main character.
- It is the fourth nicknamed Pokémon to be owned by a main character, the other three being Growlie, Caserin and Luverin.
- Its English nickname is obviously named after the word "snowy". Its Japanese nickname comes from "shiro" (which means "white"), and "koron koron" (which means "to roll around"), as stated by Lillie in "Getting to Know You!"
- It is the only Pokémon where it was hatched as an egg and caught in a Poké Ball in two different episodes.
- ^ Pokémon Sun and Moon Promotional DLC Event Manual
- ^ SM008: Lillie's Egg-xhilarating Challenge!
- ^ SM009: To Top a Totem!
- ^ SM010: Trial and Tribulation!
- ^ SM012: The Sun, the Scare, the Secret Lair!
- ^ a b SM013: Racing to a Big Event!
- ^ SM014: Getting to Know You!
- ^ SM017: Crystal-Clear Sleuthing!
- ^ SM022: A Shivering Shovel Search!
- ^ SM027: A Glaring Rivalry!
- ^ SM028: Pulling Out the Pokémon Base Pepper!
- ^ SM029: Lulled to La-La Land!
- ^ SM030: The Ol' Raise and Switch!
- ^ SM031: The Island Whisperer!
- ^ SM032: Treasure Hunt, Akala Style!
- ^ SM033: Big Sky, Small Fry!
- ^ SM039: Mallow and the Forest Teacher!
- ^ SM041: Mounting an Electrifying Charge!
- ^ SM042: Alola, Kanto!
- ^ SM043: When Regions Collide!
- ^ SM048: Night of a Thousand Poses!
- ^ SM049: Mission: Total Recall!
- ^ SM050: Faba's Revenge!
- ^ SM051: Family Determination!
- ^ SM052: Revealing the Stuff of Legend!
- ^ SM053: Rescuing the Unwilling!
- ^ SM054: 10,000,000 Reasons to Fight!
- ^ SM055: The Professors' New Adventure!
- ^ SM061: A Mission of Ultra Urgency!
- ^ SM069: Rise and Shine, Starship!
- ^ SM078: Twirling with a Bang!
- ^ SM085: The Long Vault Home!
- ^ SM067: Love at First Twirl!
- ^ SM060: Getting a Jump on the Competition!
- ^ SM080: Not Caving Under Pressure!
- ^ SM090