Siegfried (ジークフリード, Jīkufurīdo? or ジークフリート, Jīkufurīto?), also known as Ziegfried or Paladin, is a recurring character and enemy in the Final Fantasy series. He is typically presented as a mysterious swordsman of surpassing skill.
Appearances
Final Fantasy VI
Siegfried is a famous swordsman who travels the world seeking treasure. He does not play an important role in the story, but appears sporadically throughout the party's adventure. He can be fought as a boss onboard the Phantom Train and in the Dragon's Neck Coliseum. While the first encounter against him is laughably easy, he is a much more formidable foe in the Coliseum where he is one of the strongest opponents.
Lightning Returns: Final Fantasy XIII
Siegfried is a garb available to Lightning. It obtained by posting the Battle Score to the Outerworld services in the demo version of the game. Its locked ability is Relentless Assault Lv. 2, it gives no extra ATB but Lightning always starts battles in this garb with the ATB bar fully filled. It also provides Strength +10%.
Final Fantasy XIV
Two distinct enemies named Siegfried appear. The first Siegfried is an elezen dark knight encountered in 
Sigmascape V1.0, where he has a small chance of appearing in one of the train cars during the Phantom Train battle instead of the usual ghosts. This Siegfried is a much weaker opponent than the ghosts or his later appearance, referencing his Final Fantasy VI appearance.
The second Siegfried is the alter ego of Zirnberk Fyrgeissyn, commander of the Stone Torches and eldest son of Fyrgeiss Loetkilbsyn. Zirnberk performs under the Siegfried name when competing in the Masked Carnivale, and is the main antagonist of the level 50-60 blue mage questline. Siegfried is fought as a boss in stage 30 of the Masked Carnivale, The Catch of the Siegfried.
Final Fantasy Legend II
The Paladin (Siegfried in Japanese) is an enemy encountered in the Central Shrine. It is the strongest Guard-type enemy encountered.
Dissidia Final Fantasy
A ghost card named Siegfried can be acquired. The Siegfried ghost is a level 100 Kefka. A Cyan Gem and a Tintinnabulum can be won through Battlegen with the ghost, the latter a reference to the item the player can win from Siegfried in the Coliseum in Final Fantasy VI. The quote on the card "It seems that an impostor has been masquerading as me recently..." is what Siegfried says to the party in the Coliseum.
Dissidia 012 Final Fantasy
The Famed Moogle ghost card uses Siegfried's icon, and the description references Siegfried: "You know not my name? Everyone knows only the octopus..." The Famed Moogle ghost is a level 100 SSS-ranked Vaan.
Pictlogica Final Fantasy
Siegfried from Final Fantasy VI appears as a boss.
Final Fantasy All the Bravest
Siegfried from Final Fantasy VI appears as a boss.
Final Fantasy Record Keeper
Siegfried from Final Fantasy VI appears as a boss.
Mobius Final Fantasy
Etymology
Siegfried (known as "Sigurd" in Norse mythology) is the dragon-slaying hero of the German epic poem, Song of Nibelungs.