It is referred to as a Stormtrooper Officer and the one in the photo is holding an “axe-like weapon.”
Newly leaked images from Star Wars: The Last Jedi give fans another look at Supreme Leader Snoke’s Praetorian Guards, the First Order “gorilla walkers” that will be used during the battle on Crait, and a new stormtrooper outfit.
The First Order walker certainly bears resemblance to the Empire’s AT-ATs, but there are slight differences such as the cannon directly above the cockpit.
Just recently, a handful of Last Jedi rumors were seemingly confirmed when Episode VIII LEGO set packaging made its way online.