The Moogle was a bonus character in the Dissidian Wars who serves as a Assist Only Character and may or may not be Cid of the Lufaine
Despite being an Assist-only character, The Moogle has it's own set of outfits, all of which are unlocked after purchasing him.
His default costume is his appearance in Dissidia
The Moogle's first alternate outfit is as a moogle based on the Final Fantasy IX version - Ruffed, more cat-like.
And his second alternate outfit is the traditional 'Mog' moogle (FFIII-VI) - more rounded and mouse-like.
As an Assist-only character, The Moogle casts randomly upon summoning. The possibilities are the same regardless of how it was summoned