ive seen a lot of people come up with their own headcannons on what traits the different pony races have so i thought itd be fun to do that as well!  
all of the traits ive drawn here will be considered ‘pure bred’ designs, meaning these are what each race used to look like before pegasi, unicorns, and earth ponies were allowed to mate outside of their breed  
also i drew some generation 3 ponies for my examples! ive always been a fan of my little pony and these are the ones i remember most vividly
 
Pegasi  
Body:  
Pegasi are noted for having feathery coats and attributes similar to that of a bird. Their tail feathers help them steer and maintain balance while their feathered ankles aid in being more aerodynamic. Their feathered ears keep wind from rushing into the canal and making them deaf. Their feathering also aids in keeping them warm while in higher atmosphere and dealing with the elements. Pegasi range from small to medium in body size. The larger the pegasi, the harder it is for them to fly. It is considered a ‘curse’ or ‘bad omen’ when a pegasi is born with under-developed wings.
 
Behaviors:  
Pegasi are flashy by nature and look for opportunities to flaunt their magnificent wings and shiny plumage. Whistling and singing are ways that pegasi communicate and find potential mates. Males will often try to harmonize with the female or partner they are trying to attract, but usually they focus on appearance. Any pegasi will fluff out their chest and flex their wings to attract a mate. Pegasi with flashier wing patterns are often found more attractive by nature. Chest flaring and bringing a pegasis wings to full height can be a sign of aggression and most pegasi fight by batting at one another with their wings rather than trampling with hooves. Preening is friendly and loving activity that pegasi partake in. It shows trust and how close two pegasi are to each other since it is a delicate process and ruining a pegasis feathers is the worst thing that can be done.
 
 
Earth Pony  
Body:  
Earth ponies are the most diverse when it comes to breeds. Most commonly is just the pure bred. The pure bred is generally stout and hearty in body. They are muscular and bare sharp teeth that are used to fight off the creatures that dwell on the ground. One thing no pony wants to encounter is the sheer force that an earth pony can unleash from their buck. Their front legs are also strong and could trample even a dragon. Despite their short legs, pure bred can run exceedingly fast. The larger breeds pack a heavier punch but are far slower.
 
Behaviors:  
Earth ponies are extremely family oriented. They believe that the most important trait in any creature is loyalty. They make trustworthy friends and excellent partners. Earth ponies often shower their mates or potential mates with gifts of food or hand made trinkets to show they are loyal to taking care of the pony they wish to attract. Nothing beats an earth pony`s work ethnic and the dedication to their craft.
 
Unicorns  
Body:  
Unicorns are notably slender and elegant creatures. Their main focus is always on appearance and ensuring that they can attract attention to themselves. Their horns are often celebrated and many unicorns with dress up their horns with jewels to make them stand out. Horns can come in many shapes and sizes. The ‘pure’ horn is a simple spiraled and long horn. Unicorns often have long feathering on their ankles and take extra measures to ensure their hooves are never soiled. A unique feature of the unicorn is their long tail. Short tails in unicorns are considered bizarre and ‘distract’ from the elegance of their form.
 
Behaviors:  
Unicorns are considered quite snobbish creatures and demand perfection. It is expected that a unicorn have perfect manners and always keep their heads held high. Finding a mate can be a gruesome process for unicorns as there are many ways they ‘test’ their potential mate. Some of these tests include: the strength of their magic, the shape and length of horn, amount of riches, ability to dance, and finally, through dueling. Dueling is the ultimate test of love and determination a unicorn can choose. If two unicorns are competing for the same mate, they will often duel the traditional way where they charge with their horns and whomever gets speared, loses. If there is no competitor, the inquirer will often face a duel with the unicorns father.
 
Ponies names in order  
Starcatcher, Thistle Whistle, Minty, Rarity