Found out that this unnamed LEGO Arc Trooper is actually a named Clone in Season 3 episode 2 (“ARC Troopers”). He is seen for a few seconds and goes by “Hammer”. I
LEGO Set fig-003867 Clone ARC Trooper / Elite Clone Trooper with Neck Bracket (2012 Star Wars) | Rebrickable - Build with LEGO
ARC Commander Colt - Star Wars ARC Trooper Minifigures Toy 781936297527 on eBid Australia | 208696946
Clone Trooper | Brickset: LEGO set guide and database
How to make CUSTOM lego ARC TROOPERS! Custom Lego Star Wars clones tutorial | Part 1 - YouTube