Not sure if this counts, but it acts like a boss for a level and is more difficult than a slated boss from a level after it.
The Imperial Dark Troopers from Force Unleashed, the tall black storm troopers with a rocket launcher on one shoulder, an energy blade that it uses to swipe at you and used for an AoE attack, as well as hugging you then throwing you on the ground. Oh, and they are impervious to everything you can throw at them unless you use Force Lightning, so only lightning combos, Lightning itself, and shock thrown object.
Yeah fuck them, not only do they make the first appearance three times in the same level, they are also prevalent on levels after them in great numbers, especially on the Death Star, where they are always in the perfect place to launch a rocket at you and knock you off from where ever you happen to be standing. Kazdan, Shak Ti, Darth Vader, they can all twiddle on me with their glow sticks as much as they want, but these fucks can all be thrown out an airlock and blown up by the Death Star.