Not much known is about his backstory. But eventually, he voice could be heard through the Echo Flower, and theorized where he had met Sans at the bench room where the Abandoned Quiche was.
Riolu is a short-haired tomcat with blue-gray fur, blue eyes, a yellow collar, and a Pokéball collar tag. He is a very kind and generous feline, but he can be childish sometimes.
The protagonist must must take the Abandoned Quiche in the bench room when the computer's clock is set for February 20 at 5 PM to encounter him. This encounter must happen before the second encounter with Undyne, or Riolu will not come.
It was a cold morning on February 19th, 2000. A calico cat named Anne lived in a mansion in Illinois with her two loving owners. She was pregnant with six kittens and at full term. She was ready to give birth. She went to her bed to give birth. Within minutes, her kittens were born. When she looked at them, she saw that three of her kittens had unique colors. One was grey-blue, one was pink, and one was light blue with blue markings. She named the blue-gray one Riolu, the pink one Chloe, and the light blue one Callie. Anne loved her kittens very much.
On February 21st at 8:30 pm, When Anne was taking care of her kittens, her owners were about to plug in their new lamp they bought at the store. But when they plugged it in, it caused an electrical spark, setting the house on fire. The fire spread quickly and couldn’t be stopped. Anne and her kittens escaped the burning house, but her owners were crushed under the collapsing house. Luckily, some firemen from a local Fire Department came and put out the fire. Anne was shocked and heartbroken that she lost her owners.
On February 22nd at 12:00 pm, Anne became a stray and walked around the city of Arlington Heights with her kittens on her back. She missed her owners very much. However, some strange men arrived and saw Anne. The men were stray cat hunters who find stray cats and take them to loving owners around the world. The men snatched Anne and took her away. The kittens were separated from their mother. However, a woman arrived and saw the kittens. She wasn’t very surprised to see them so she snatched them up and took them to an orphanage.
On February 23rd at 6:30 pm, the kittens were abused by the orphanage owner. The woman just kept kicking them, punching them, and yelling at them. The woman was somehow a cat hater. The kittens couldn’t take the abuse.
At 11:30 pm, the kittens woke up in the middle of the night to plan their escape. First, they packed some food, some water, and their favorite things. After that, they snuck around the orphanage to find the exit. After a couple minutes, they found the exit and run away to find their mother.
Morning came and the kittens hadn’t found their mother yet. It started to rain and the kittens decided to hide in the suitcase they packed their stuff in and waited for the rain to pass by. Riolu didn’t want his siblings to suffocate in the suitcase, so he found a stick to keep the suitcase slightly open. When the kittens were asleep, they had a flashback to when they were kept warm and safe by their mother.
At 2:00 pm, the rain finally stopped and the kittens were asleep. Suddenly, a large pink cat with a white belly, a diamond-studded collar, and a hot pink heart-shaped mark on her back came to the kittens and licked them. Most people called her Mother Cat. She asked the kittens why they were hiding in a suitcase by themselves, and the kittens told her they tried to find their mother, but they never found her. Mother Cat felt bad for the kittens and decided to take care of them so she could be their new mother.
Hours pass and Mother Cat built a den made out of sticks and branches. The den was built on a mountain-side. The kittens were loved by Mother Cat and were happy to be away from that orphanage. Mother Cat hunted mice and rabbits and cooked them for the kittens to eat. She was also able to find fresh water for the kittens to drink.
Later that day, Mother Cat stared at the mountain. The kittens joined her and watched many birds fly by. They even felt the warm breeze. Mother Cat and the kittens closed their eyes and began to meditate. However, minutes pass and their meditation was interrupted by a rumble in the ground. Mother Cat and the kittens looked around to see what was going on, only to find the mountain revealing itself as a volcano as it was about to blow its top. Lava oozed down the volcano. Mother Cat and the kittens ran away from the volcano and took the suitcase with them.
As Mother Cat and the kittens kept running, they came across a rescue helicopter. The pilots were boarding the helicopter. Mother Cat and the Kittens ran towards the helicopter and had enough time to board it. Their suitcase was safe too. The helicopter took off and the pilots searched for anyone who was in danger.
After hours of rescue, there was no one left behind. Everyone was rescued and the helicopter headed to Michigan.
Later that day, the helicopter came to a helicopter base in a city in Michigan. Mother Cat was quite glad to be back in her home state again. She decided to take the kittens to her home.
Hours passed and it was getting dark. Mother Cat and the kittens were lost in the forest that night, but they came across Mother Cat’s mansion, so they went in. After entering the house, Mother Cat put the kittens in her bed. She kissed them goodnight and slept with them, keeping them warm and safe.
It was February 25th, and Riolu, Silver, and Chloe were playing outside. They romp around and play in the forest. After a while, they saw a butterfly and chase after it.
After a long time of chasing after that butterfly, Riolu and Chloe found themselves separated from Silver. They called out to him, but there was no answer. They were worried about him and though that he may have gotten killed. Riolu and Chloe hugged each other and sobbed, but that’s when a strange man wearing a robe appeared. He was a sorcerer. Riolu and Chloe stared at him in shock and awe. The sorcerer casted a spell on the two kittens, turning them into full-grown cats in just three seconds. Riolu and Chloe were shocked to see they were full-grown already. The sorcerer then gave them two collars with PokéBall collar tags on them. The cats ran back to Mother Cat’s mansion and the sorcerer waved goodbye to them.
When Riolu and Chloe got back, they talked to Mother Cat, who was quite surprised to see them full-grown already. She still remembered them, luckily. Chloe told Mother Cat that Silver had gone missing, and Mother Cat was shocked and worried.
Two days passed and Riolu took a walk on the beach, when she saw a cat with a robotic arm. He realized that it was his brother Silver. Riolu and Silver hugged each other and cried tears of joy. Then they headed back to Mother Cat’s mansion.
The kittens were back together as they took a walk to the beach with Mother Cat. However, the sorcerer appeared in front of them and explains everything he did for Riolu. Then he had a surprise for him. He used his magic and something appeared. It was Riolu’s new home, the PokéClubhouse. Riolu and his siblings were sad to be separated from Mother Cat, but they were happy to have their own home now. They waved goodbye to Mother Cat and went into their new home.
This power allows Riolu to bring his friends and loved ones back to life only if they're killed. This power requires a 5 - 10 days recharge, depending on a specific death. Riolu can only restore life if the deceased person's soul hasn't left their body.
This power allows Riolu to return the ones who are corrupted back to normal. This power requires 10 - 15 days recharge. If reached 15 days, then the chance of destroying corruption is at 50%, as the other 50% would fail.
Riolu got this Rage Form when he was injected with the G-Virus. In this form, both of his eyes have the same pupil as Normal Rage. His right arm is larger than his left arm, and it has larger claws, and a large bloodshot eye, which came from the G-Virus, is in the shoulder. The Pokéball collar tag turns into a Master Ball.
Riolu's last and most deadliest Rage Form. In this form, Riolu is now larger than a two-story building while standing on all fours. The 20 claw tentacles implanted in his back can spring out and reach 10 miles. He also has eight eyeball arms, four on each side. His tail becomes a tail sword. The Pokéball collar tag turns into a Luxury ball.
Riolu likes to inflate his belly. He mostly uses air, helium, or water to inflate himself. He can also inflate his belly to massive sizes when he's wearing the Nonstop Inflator, which was obtained from Martin.
"♫ "Go ahead and try to hit me if you're able. Can't you see that my relationship is stable? I can see you hate the way we intermingle. But I think you're just mad 'cause you're single." ♫
♫ "I am their fury, I am their patience, I am a conversation. ♫
♫ I am made o-o-o-o-of lo-o-o-o-ove. (of love)" ♫" – Riolu, during the song "Stronger Than You"