Pathfinding Axejaw

When Pathfinding Axejaw enters, it explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard.)

Sage of Days

When Sage of Days enters, look at the top three cards of your library. You may put one of those cards back on top of your library. Put the rest into your graveyard.

Staggering Size

Target creature gets +3/+3 and gains trample until end of turn.

Seeker of Sunlight

{2}{G}: Seeker of Sunlight explores. Activate only as a sorcery. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard.)

Frilled Cave-Wurm

Descend 4 — Frilled Cave-Wurm gets +2/+0 as long as there are four or more permanent cards in your graveyard.

Walk with the Ancestors

Return up to one target permanent card from your graveyard to your hand. Discover 4. (Exile cards from the top of your library until you exile a nonland card with mana value 4 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.)

Song of Stupefaction

Enchant creature or Vehicle
When Song of Stupefaction enters, you may mill two cards. (You may put the top two cards of your library into your graveyard.)
Fathomless descent — Enchanted permanent gets -X/-0, where X is the number of permanent cards in your graveyard.

River Herald Scout

When River Herald Scout enters, it explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard.)

Malamet Veteran

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.

Forest

Basking Capybara

Descend 4 — Basking Capybara gets +3/+0 as long as there are four or more permanent cards in your graveyard.

River Herald Guide

Vigilance
When River Herald Guide enters, it explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard.)

Island

Huatli's Final Strike

Target creature you control gets +1/+0 until end of turn. It deals damage equal to its power to target creature an opponent controls.

Waterwind Scout

Flying
When Waterwind Scout enters, create a Map token. (It's an artifact with "{1}, {T}, Sacrifice this artifact: Target creature you control explores. Activate only as a sorcery.")