Dwarf Engineer is a boss added by Better Dungeons. He is riding on a Mecha Golem. He hits you for 4 hearts (8 damage) for no armor on. He does not suffer knockback ,but he knocks back you with his gun spear.He is difficult because he and have 100 HP (50 hearts) which is a lot and same thing with other mobs, when he low on health he's backup and drink his potion. His mecha golem hit with its stone sword and shoot with its left arm
Dwarf Engineer spawn in Volcano in the room. Inside his room has a loot in the chest. He can also spawn using the item that same as Mecha golem spawn item.
Dwarf Engineer drops Gun spear, diamond, experience and sometime healing potion