Persistent Specimen

{2}{B}: Return Persistent Specimen from your graveyard to the battlefield tapped.

Tenacious Dead

When Tenacious Dead dies, you may pay {1}{B}. If you do, return it to the battlefield tapped under its owner's control.

Reassembling Skeleton

{1}{B}: Return this card from your graveyard to the battlefield tapped.

Sefris of the Hidden Ways

Whenever one or more creature cards are put into your graveyard from anywhere, venture into the dungeon. This ability triggers only once each turn. (To venture into the dungeon, enter the first room or advance to the next room.)
Create Undead — Whenever you complete a dungeon, return target creature card from your graveyard to the battlefield.