Are all of Terramorphous' Class Mod drops the same?
When farming Terramorphous last night we found that he exclusively dropped orange Class Mods with nearly identical effects (he dropped other loot, but the orange loot was always a single mod, every time). All of these had +4 to 6 different skills, and +20% to 25% Burn damage and Burn Effect Chance, and + some amount of max health.
These mods are really fairly useless, aside from the skill bonus. They're okay for Siren (still sub-par burn %s however) but do they really only drop Burn Damage or did we get an unlucky batch? I saw Gunzerker, Assassin and Siren mods. The 2 Siren mods were identical, and the non-siren mods all had the burn chance and health bonuses.
Turns out he has very rare legendary class mods of the form "Legendary (class) mod" that reference the quotes and abilities of the original Vault Hunters.
Some details are here for the special effects, like the Slayer of Terramorphous mods they give +5 (instead of 4) to several level 1 skills.
Legendary Siren gives +35%(ish) cooldown rate, +28%(ish) gun damage, and +5 to the following skills: Ward, Acelterate, Mind's Eye, Flicker and Foresight. Also increases movement speed by 45% while Phaselocking (similar to the Phasewalk speed boost).
Judging from at Siren one at least, they are considerably better than the Slayer of Terra mods, especially if you find the burn damage useless.