Giant Beaver

Vigilance
Whenever this creature attacks while saddled, put a +1/+1 counter on target creature that saddled it this turn.
Saddle 3 (Tap any number of other creatures you control with total power 3 or more: This Mount becomes saddled until end of turn. Saddle only as a sorcery.)

Goblin Medics

Whenever this creature becomes tapped, it deals 1 damage to any target.

Nimble Mongoose

Shroud (This creature can't be the target of spells or abilities.)
Threshold — This creature gets +2/+2 as long as seven or more cards are in your graveyard.

Trace of Abundance

Enchant land
Enchanted land has shroud. (It can't be the target of spells or abilities.)
Whenever enchanted land is tapped for mana, its controller adds an additional one mana of any color.

Deft Duelist

First strike
Shroud (This creature can't be the target of spells or abilities.)

Deepwater Hypnotist

Inspired — Whenever this creature becomes untapped, target creature an opponent controls gets -3/-0 until end of turn.

Oreskos Sun Guide

Inspired — Whenever this creature becomes untapped, you gain 2 life.

Stonybrook Schoolmaster

Whenever this creature becomes tapped, you may create a 1/1 blue Merfolk Wizard creature token.

Moonfolk Puzzlemaker

Flying
Whenever this creature becomes tapped, scry 1.

Scaretiller

Whenever this creature becomes tapped, choose one —
• You may put a land card from your hand onto the battlefield tapped.
• Return target land card from your graveyard to the battlefield tapped.

Night Market Lookout

Whenever this creature becomes tapped, each opponent loses 1 life and you gain 1 life.

Throw from the Saddle

Target creature you control gets +1/+1 until end of turn. Put a +1/+1 counter on it instead if it's a Mount. Then it deals damage equal to its power to target creature you don't control.

Silhana Ledgewalker

Hexproof (This creature can't be the target of spells or abilities your opponents control.)
This creature can't be blocked except by creatures with flying.

Hangar Scrounger

Backup 1 (When this creature enters, put a +1/+1 counter on target creature. If that's another creature, it gains the following ability until end of turn.)
Whenever this creature becomes tapped, you may discard a card. If you do, draw a card.

Zhur-Taa Druid

{T}: Add {G}.
Whenever you tap this creature for mana, it deals 1 damage to each opponent.

Jade Guardian

Hexproof (This creature can't be the target of spells or abilities your opponents control.)
When this creature enters, put a +1/+1 counter on target Merfolk you control.

Trained Arynx

Whenever this creature attacks while saddled, it gains first strike until end of turn. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
Saddle 2 (Tap any number of other creatures you control with total power 2 or more: This Mount becomes saddled until end of turn. Saddle only as a sorcery.)

Vampire Envoy

Flying
Whenever this creature becomes tapped, you gain 1 life.

Jungleborn Pioneer

When this creature enters, create a 1/1 blue Merfolk creature token with hexproof. (It can't be the target of spells or abilities your opponents control.)

Drover Grizzly

Whenever this creature attacks while saddled, creatures you control gain trample until end of turn.
Saddle 1 (Tap any number of other creatures you control with total power 1 or more: This Mount becomes saddled until end of turn. Saddle only as a sorcery.)

Judge of Currents

Whenever a Merfolk you control becomes tapped, you may gain 1 life.

Merrow Bonegnawer

{T}: Target player exiles a card from their graveyard.
Whenever you cast a black spell, you may untap this creature.

Volatile Wanderglyph

Whenever this creature becomes tapped, you may discard a card. If you do, draw a card.

Quilled Charger

Whenever this creature attacks while saddled, it gets +1/+2 and gains menace until end of turn. (It can't be blocked except by two or more creatures.)
Saddle 2 (Tap any number of other creatures you control with total power 2 or more: This Mount becomes saddled until end of turn. Saddle only as a sorcery.)

Bridled Bighorn

Vigilance
Whenever this creature attacks while saddled, create a 1/1 white Sheep creature token.
Saddle 2 (Tap any number of other creatures you control with total power 2 or more: This Mount becomes saddled until end of turn. Saddle only as a sorcery.)

Slippery Bogle

Hexproof (This creature can't be the target of spells or abilities your opponents control.)

Steer Clear

Steer Clear deals 2 damage to target attacking or blocking creature. Steer Clear deals 4 damage to that creature instead if you controlled a Mount as you cast this spell.

Humble Budoka

Shroud (This creature can't be the target of spells or abilities.)

Conduit Pylons

When this land enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
{T}: Add {C}.
{1}, {T}: Add one mana of any color.

Elvish Lookout

Samite Herbalist

Whenever this creature becomes tapped, you gain 1 life and scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Jade Bearer

When this creature enters, put a +1/+1 counter on another target Merfolk you control.

Gladecover Scout

Scythe Tiger

Shroud (This creature can't be the target of spells or abilities.)
When this creature enters, sacrifice it unless you sacrifice a land.