Dungeons & Dragons: Adventures in the Forgotten Realms

Triumphant Adventurer | Creature | Human Knight | Deathtouch As long as it's your turn, Triumphant Adventurer has first strike. Whenever Triumphant Adventurer attacks, venture into the dungeon. (Enter the first room or advance to the next room.) | Alexander Mokhov

Barrowin of Clan Undurr | Legendary Creature | Dwarf Cleric | When Barrowin of Clan Undurr enters the battlefield, venture into the dungeon. (Enter the first room or advance to the next room.) Whenever Barrowin of Clan Undurr attacks, return up to one creature card with mana value 3 or less from your graveyard to the battlefield if you've completed a dungeon. | Manuel Castañón

Tiamat | Legendary Creature | Dragon God | Flying When Tiamat enters the battlefield, if you cast it, search your library for up to five Dragon cards not named Tiamat that each have different names, reveal them, put them into your hand, then shuffle. | Chris Rahn