Emmet

Physical Appearance
He is an alicorn stallion with a golden yellow coat, dark brown eyes, light brown mane and tail, and a dark blue wrench as his cutie mark

Steve's Journey
Though not mentioned by name, he appears in the epilogue along with Breezylight, Twilight, Eclipse, Lucky Gear, Steve, and Alex, heading toward Jesse and Petra

Trivia

 * He is the mentor of Breezylight
 * In the original script, Emmet actually had a brother
 * He is based on the character from "The Lego Movie"