Titans of the Frontier: Mark X Obliterator

From publisher blurb: A raid boss stirs in The Frontier! Bring your best guns and wear your heaviest armor cause this is a foe that doesn't fear even max-level parties! The Obliterator is the heaviest battle mech ever made, with enough firepower to take on a small army by itself. If you're looking for something to truly challenge your players, this level 15 steel titan will give them the fight of their lives.