[u]Vanilla[/u] Terramorphous the Invincible - Mission unlocked after beating the story, minimum level 50. Drops (Guaranteed) Slayer of Terramorphous class mod (random class) - (Possible) Hide of Terramorphous, Breath of Terramorphous, Teeth of Terramorphous, Breath of Terramorphous, Pitchfork Vermivourus the Invincible - Varkid reaching highest level of evolution, only possible in TVHM or UVHM, more likely the more people in the group, easiest areas the Farmhouse in Tundra Express, Caustic Caverns,the Varkid round of Animal Slaughter or Wam Bam Island. Drops (Guaranteed) Norfleet, Nasty Suprise, Skins & Heads [u]Captain Scarlet & Her Pirate Booty[/u] Hyperious the Invincible - Unlocked after beating the DLC story. Drops (Guaranteed) Seraph Crystals & Tattler or the Retcher. (Possible) Norfleet, Whisky Tango Foxtrot, Hornet, the Moxxi Grenade (forgot the name) & a few others I think Master Gee the Invincible - Unlocked after beating Hyperious. Drops (Guaranteed) Seraph Srystals & Patriot or Ahab - (Possible) Another pool of legendaries like hyperious but can't remember what they are. [u]Mr Torgues Campaign of Carnage[/u] Pyro Pete the Ultra Invincible - unlocked after beating the DLC story. Drops (Guaranteed) Seraph Crystals & Big Bloom Blaster or, some seraph grenade mod, forgot which one - (Possible) Any legendary Grenade mod [u]Sir Hammerlocks Big Game Hunt[/u] Voraciduous the Invincible -unlocked after beating the DLC story (Also the hardest). Drops (guaranteed) Seraph Crystals & The Interfacer or the Hawkeye Dexiduos the invinicble - Summoned by sacrificing 200 Eridium in various shrines in Hunter's Grotto, and fighting off a few Waves of savages. Drops (Possible) The Chopper] [u]Tiny Tina's assault on Dragon Keep[/u] Ancient Dragons of Destruction - unlocked after beating the DLC story & Mr Torgue's Sidequest. Drops (Guaranteed) Seraph Crystals, large amount of Eridium, Large number of chests, the Omen or a Seraph Anshin Shield, can't remember its name [u]Head Hunter Packs[/u] The Invincible Son of Crawmerax the Invincible - unlocked after beating Headhunter Pack 5's story. Drops Nothing special [u]Honorable Mentions[/u] Ohmd Ohmd Ohk - Summoned when a badass Savage is leveled by a Witch Doctor the maximum number of times. Drops (Possible) The Twister Iron God - Summoned when a Golem from the Tiny Tina DLC is leveled the maximum number of times, drops nothing but is the Highest leveled an enemy in Borderlands can be compared to the player, something like 92 OMGWTH (in Binary) - Final boss in Digistruct Peak at levels OP7 & OP8. Drops (Guaranteed, OP8 only) any of the Gen 1 Pearlescent weapons (can't remember most of them as they all suck)

Terramorphous Pyro Pete Master Gee the Invincible Hyperius the Invincible Vermivorous Dexidious (I think) Ancient Dragons of Destruction Don't know if I missed any.