WolfHero
Official Terrarian
Everything in hardmode dungeons. Notably annoying though are the Diabolist and Necromancer for teleporting around and generally making dungeon farms terrible. There are also the Paladins which have remarkably fast, heavy-hitting hammers and tons of HP, and of course Bone Lee deserves an honorable mention for having the ability to phase/glitch through the ground to make dungeon farms even less viable.