Trumpeting Carnosaur

Trample
When Trumpeting Carnosaur enters, discover 5.
{2}{R}, Discard Trumpeting Carnosaur: It deals 3 damage to target creature or planeswalker.

Calamity, Galloping Inferno

Haste
Whenever Calamity, Galloping Inferno attacks while saddled, choose a nonlegendary creature that saddled it this turn and create a tapped and attacking token that's a copy of it. Sacrifice that token at the beginning of the next end step. Repeat this process once.
Saddle 1

Bristling Backwoods

Bristling Backwoods enters tapped.
When Bristling Backwoods enters, it deals 1 damage to target opponent.
{T}: Add {R} or {G}.

Glimpse the Core

Choose one —
• Search your library for a basic Forest card, put that card onto the battlefield tapped, then shuffle.
• Return target Cave card from your graveyard to the battlefield tapped.

Rabid Gnaw

Target creature you control gets +1/+0 until end of turn. Then it deals damage equal to its power to target creature you don't control.

Axebane Ferox

Deathtouch, haste
Ward—Collect evidence 4. (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player exiles cards with total mana value 4 or greater from their graveyard.)

Overlord of the Boilerbilges

Impending 4—{2}{R}{R} (If you cast this spell for its impending cost, it enters with four time counters and isn't a creature until the last is removed. At the beginning of your end step, remove a time counter from it.)
Whenever Overlord of the Boilerbilges enters or attacks, it deals 4 damage to any target.

Colossal Rattlewurm

Colossal Rattlewurm has flash as long as you control a Desert.
Trample
{1}{G}, Exile Colossal Rattlewurm from your graveyard: Search your library for a Desert card, put it onto the battlefield tapped, then shuffle.

Untimely Malfunction

Choose one —
• Destroy target artifact.
• Change the target of target spell or ability with a single target.
• One or two target creatures can't block this turn.

Enduring Courage

Whenever another creature you control enters, it gets +2/+0 and gains haste until end of turn.
When Enduring Courage dies, if it was a creature, return it to the battlefield under its owner's control. It's an enchantment. (It's not a creature.)

Mountain

Tyrranax Rex

This spell can't be countered.
Trample, ward {4}, haste
Toxic 4 (Players dealt combat damage by this creature also get four poison counters.)

Kogla and Yidaro

When Kogla and Yidaro enters, choose one —
• It gains trample and haste until end of turn.
• It fights target creature you don't control.
{2}{R}{G}, Discard Kogla and Yidaro: Destroy up to one target artifact or enchantment. Shuffle Kogla and Yidaro into your library from your graveyard, then draw a card.

Railway Brawler

Reach, trample
Whenever another creature you control enters, put X +1/+1 counters on it, where X is its power.
Plot {3}{G} (You may pay {3}{G} and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)

Conduit Pylons

When Conduit Pylons 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.

Forest

Smuggler's Surprise

Spree (Choose one or more additional costs.)
+ {2} — Mill four cards. You may put up to two creature and/or land cards from among the milled cards into your hand.
+ {4}{G} — You may put up to two creature cards from your hand onto the battlefield.
+ {1} — Creatures you control with power 4 or greater gain hexproof and indestructible until end of turn.

Outcaster Trailblazer

When Outcaster Trailblazer enters, add one mana of any color.
Whenever another creature you control with power 4 or greater enters, draw a card.
Plot {2}{G} (You may pay {2}{G} and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)

Restless Ridgeline

Restless Ridgeline enters tapped.
{T}: Add {R} or {G}.
{2}{R}{G}: Restless Ridgeline becomes a 3/4 red and green Dinosaur creature until end of turn. It's still a land.
Whenever Restless Ridgeline attacks, another target attacking creature gets +2/+0 until end of turn. Untap that creature.