The Lost Caverns of Ixalan

Oltec Archaeologists | Creature | Human Artificer Scout | When Oltec Archaeologists enters the battlefield, choose one — • Return target artifact card from your graveyard to your hand. • Scry 3. (Look at the top three cards of your library, then put any number of them on the bottom and the rest on top in any order.) | Winona Nelson

Didact Echo | Creature | Spirit Cleric | When Didact Echo enters the battlefield, draw a card. Descend 4 — Didact Echo has flying as long as there are four or more permanent cards in your graveyard. | Irina Nordsol

Primordial Gnawer | Creature | Insect Horror | When Primordial Gnawer dies, discover 3. (Exile cards from the top of your library until you exile a nonland card with mana value 3 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.) | Maxime Minard

Panicked Altisaur | Creature | Dinosaur | Reach {T}: Panicked Altisaur deals 2 damage to each opponent. | Lars Grant-West

Malamet Veteran | Creature | Cat Warrior | Trample Descend 4 — Whenever Malamet Veteran attacks, if there are four or more permanent cards in your graveyard, put a +1/+1 counter on target creature. | Steve Prescott