Is Sedraxis Specter legal in Standard, Modern, and Commander?

Sedraxis Specter is legal in: Modern, Legacy, Vintage, Commander.

What type of card is Sedraxis Specter?

Sedraxis Specter is a Creature — Specter. Its oracle text reads: "Flying Whenever this creature deals combat damage to a player, that player discards a card. Unearth {1}{B} ({1}{B}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)"

Sedraxis Specter

Creature — Specter

Flying

Whenever this creature deals combat damage to a player, that player discards a card.

Unearth (: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)