The First Order Dreadnought is a Mandator-IV dreadnought used by the First Order during their conflict with the Resistance in Star Wars: The Last Jedi. It acts as an orbital gun platform, and had access to two orbital guns as well as 24 cannons on the ventral side, which are comparatively flat.
New First Order vehicles from Star Wars: The Last Jedi were revealed on The Star War Show. Hosts Andi Gutierrez and Anthony Carboni showed off the AT-M6 (All Terrain Megacaliber 6) also known as the First Order Heavy Assault Walker, this is a mobile heavy artillery walker will used by the First Order during their face off against the Resistance on the planet Crait. It’s much larger than the AT-AT All Terrain Armored Transport used by the Galactic Empire, the walker features a megacaliber six cannon mounted to its back, for which it was named.
Bit of Fan Art I created of the AT-M6 in The Battle of Crait.