2014: I remember having a picture of a pony OC made in Generalzoi’s pony creator with a pair of triangular tank tracks for hind hooves and a small missile launcher and autocannon for weapons… For some reason. I don’t exactly remember if his name was “Axle” or something like that, in fact I don’t if it had the rocket launcher or the cannon so I threw both in just in case, the exact mane is also uncertain.  
It’s unknown if Axle was an inspiration for the creation of Trackhead but since he shares vague similarities to him I decided to add him to the chronology. I should mention that his colors were recycled for the newer designs of Gearbox, Trackhead’s big brother.
 
June 2015: the initial design, he also had the preliminary name of “Gearhead”. Don’t ask me why I did shape his mane like a leaf or what the tail was supposed to be.
 
August 2015: The longest used design so far, many sub designs of this version have been drawn over time with different shape for the fenders, wings for the rear or not, different ammounts of wheels,…
 
July 2017: This one is a mix of the previous design and a unused redesign drawn by a friend of mine granting the more robotic look the previous version lacked.
 
June 2018: The current design for now. Trackhead departs from the previous draft to scrap his tracked chassis for two pairs of transformable hooves that give him the hability of transform into a agile half-track mode (story change pending).