Image imported from derpibooru 
Original Description:
 
“It’s so good to see you!”
 
“He’s gotten so big!”
 
“I can’t believe it’s been so long!”
 
“How’s Twilight doing?”
 
Dewey watched the adults in mild curiosity as they greeted and hugged each other, tolerated the odd hair ruffle from Discord and encouraging nudges from Fluttershy.
 
However, his main interest lay in the mini green and pink version of Uncle Discord he was told so excitedly about by his parents. Only, he was nowhere to be seen.
 
Dewey ignored the adults and trotted about, circling around an amused Starlight and Discord, searching.
 
“Dew Drop!” Fluttershy called out softly. “Don’t you want to say hello to Starlight and Discord?”
 
Dewey disregarded his mother’s words and instead looked up at Starlight. She smiled down at him and said hello.
 
“Where’s the kid,” he replied, very bluntly.
 
Rainbow cleared her throat. “‘Oh, it’s so good to see you too, Auntie Starlight!’ would be a good response.”
 
Starlight waved her hoof dismissively. “Oh, it’s okay Rainbow. I know he’s just excited to meet his new friend.” She smiled at Dewey again, this time more knowingly. “Don’t worry, hun. He’s just very shy and hiding in plain sight. Ah, so to speak.”
 
Suddenly, there was a loud gasp and something just…appeared on Starlight’s leg. Dewey peered at it while his mothers jumped in surprise. Starlight just chuckled, placing a gentle hoof over it. “Why, Fia! How nice of you to join us! I was wondering why my leg felt so numb!”
 
The thing turned out to be just a kid. No. Dewey squinted. No, it was the kid. He look exactly how Dewey imagined. A mini, chubby Discord look-a-like with a pink head, a green body, a dark pink snake tail and, from what Dewy could see, a donkey leg and a tiger paw, which clenched tightly on his mother’s leg.
 
“C’mon, son!” Discord said, encouragingly. “Don’t you want to say hi to the best godson in the world!”
 
Dewey sat just beneath Fluttershy as the kid slowly turned his head. He didn’t have an antler or a horn like Dscord but did have a normal looking unicorn horn at the base of his green and purple hair. His eyes were both blue and yellow, full of watery nervousness like a sad puppy just separated from its family.
 
He was so weird-looking. Dewey’s lips curled into a very small smile. He was perfect.
 
“Hey, Tigerpaw,” he said, making Fiasco squeak. “What’s up?”
 
-
 
To cut a long story short, Fiasco was very sick at an early age. He spend the first part of his childhood at a hospital/hospice which he barely left as Starlight and Discord frantically searched for a cure. Many of the other kids and even the parents rejected or ignored Fiasco due to his appearance and parents’ histories, thus making it very difficult to make friends and leaving him very shy and meek.
 
Eventually, they found a cure and as soon as Fia was well enough, the Starcord Family packed their bags and moved house to Ponyville (literally, Discord had his clones fly it in from Sire’s Hollow). The family themselves travelled by train and met the Flutterdash family at the station.
 
At this point, the last time Fia saw Dewey was when they were very small babies. To him, though, this pegasus was just a very quiet and kinda scary stranger who had very little or no emotion. Luckily, Dewey liked him and very slowly, helped Fia come out of his shell to become the troublesome little boy that made Daddy Discord proud.
 
Fillies: Dew Drop  
Fiasco