Relic's Roar

Until end of turn, target artifact or creature becomes a Dinosaur artifact creature with base power and toughness 4/3 in addition to its other types.

River Herald Scout

When this creature 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 this creature 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.

Self-Reflection

Copy

Create a token that's a copy of target creature you control.
Flashback {3}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Shipwreck Sentry

Defender
As long as an artifact entered the battlefield under your control this turn, this creature can attack as though it didn't have defender.

Sinuous Benthisaur

When this creature enters, look at the top X cards of your library, where X is the number of Caves you control plus the number of Cave cards in your graveyard. Put two of those cards into your hand and the rest on the bottom of your library in a random order.

Song of Stupefaction

Enchant creature or Vehicle
When this Aura 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.

Spyglass Siren

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

Staunch Crewmate

When this creature enters, look at the top four cards of your library. You may reveal an artifact or Pirate card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Dauntless Dismantler

Artifacts your opponents control enter tapped.
{X}{X}{W}, Sacrifice this creature: Destroy each artifact with mana value X.

Subterranean Schooner

Whenever this Vehicle attacks, target creature that crewed it this turn 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 that creature, then put the card back or put it into your graveyard.)
Crew 1

Tishana's Tidebinder

Flash
When this creature enters, counter up to one target activated or triggered ability. If an ability of an artifact, creature, or planeswalker is countered this way, that permanent loses all abilities for as long as this creature remains on the battlefield. (Mana abilities can't be targeted.)

Unlucky Drop

Target artifact or creature's owner puts it on their choice of the top or bottom of their library.

Waterlogged Hulk

{T}: Mill a card. (Put the top card of your library into your graveyard.)
Craft with Island {3}{U} ({3}{U}, Exile this artifact, Exile an Island you control or an Island card from your graveyard: Return this card transformed under its owner's control. Craft only as a sorcery.)

Watertight Gondola

Vigilance
Descend 8 — This Vehicle can't be blocked as long as there are eight or more permanent cards in your graveyard.
Crew 1 (Tap any number of creatures you control with total power 1 or more: This Vehicle becomes an artifact creature until end of turn.)

Waterlogged Hulk // Watertight Gondola

Waterwind Scout

Waylaying Pirates

When this creature enters, if you control an artifact, tap target artifact or creature an opponent controls and put a stun counter on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)

The Lost Caverns of Ixalan