The neck of the Keyblade appears to be that of a skeletal dragon, of which still has life in some of it. Unlike most Keyblades, this Keyblade features a curved neck. The handle is the landmark that defines The Underworld and is seen on the River Styx. The token is the Hades Cup.
The Fatal Crest gives the largest Magic stat boost of any Keyblade (a boost of +5), making it a good Keyblade to use when using Wisdom Form. Its usefulness for this is eclipsed in Kingdom Hearts II Final Mix by the Winner's Proof Keyblade, boasting a higher Magic boost of +7.
The Valor Form edition of the Play Arts Figures comes packaged with Fatal Crest as one of the Keyblades. Ironically, Fatal Crest is best used for its magical capabilities—and since Berserk Charge requires a complete loss of MP, Fatal Crest is essentially useless for Valor Form as the use of magic is sealed during this form.