Applebloom: Sugar, ye ever thought about looking for a talent?
Blankie: Awww c'mon Ma!
Applebloom: I ain't calling ye useless, but I feel like you don't got a path in life!
Blankie: I consider my marklessness a ploy! Tons of ponies stare at my ass, so that's a plus.

Et voila, D'arcy Spice. Last of the CMC's kids.
Most ponies call him Blankie or Blanket. One is endearing and the other is an insult.
His classmates really like him, in spite of the two nicknames he has.

Blankie is WAY too old to not have his cutiemark but that doesn't really bother him. He's not super good at anything but he also does a decent job at any task he's given. He's dependable and easy to get along with and is a master at defusing heated confrontations.

Some facts:

-After a little farming accident, the cartilage in Blankie's ear bent giving him a puppy-dog appearance that matches his puppy-dog energy.

-His BFFs are Gemini Sparkle and Aurora Toile though he has been seen doing manual labor for Scootaloo's son Chipper Chaplet.
They are the few people that could care less about his cutiemark situation as neither Gem or Rory can biologically get one either.

-Blankie dates ALOT, and seems to be the focus of many crushes at the school of Friendship just like his cousin [the town hoe] Redlove. He's a big harmless doofus who rarely poses as much of a challenge to seduce. Blankie will go along with anything but only Gem and Rory know who he's genuinely interested in. Every other week it's a new mare and occasionally stallion. None last that long.

-His mom AB feels like a failure for not helping him find his cutiemark but his dad Pip doesn't care or notice as he travels a lot. Blankie can feel the disappointment in his mother and actively avoids her because of it. The Apple family is also highly critical however he doesn't live on Sweet Apple Acres so he doesn't have to deal with them much.

-If I were to imagine a voice actor for him, I imagine he sounds like Danny Avidan from Game Grumps. He's very chill and laughs a lot.