Skithiryx, the Blight Dragon is a mythic Legendary Creature — Phyrexian Dragon Skeleton card from Secret Lair Drop (SLD), collector number 1562. Current market price: $27.22, TCGplayer market prices via Scryfall.
Flying Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.) {B}: Skithiryx gains haste until end of turn. {B}{B}: Regenerate Skithiryx.