Spellbreaker Behemoth

This spell can't be countered.
Creature spells you control with power 5 or greater can't be countered.

Thunder-Thrash Elder

Devour 3 (As this enters, you may sacrifice any number of creatures. This creature enters with three times that many +1/+1 counters on it.)

Shock

Bloodbraid Elf

Haste (This creature can attack and {T} as soon as it comes under your control.)
Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)

Incinerate

Incinerate deals 3 damage to any target. A creature dealt damage this way can't be regenerated this turn.

Mountain

Tukatongue Thallid

When Tukatongue Thallid dies, create a 1/1 green Saproling creature token.

Algae Gharial

Shroud (This creature can't be the target of spells or abilities.)
Whenever another creature dies, you may put a +1/+1 counter on Algae Gharial.

Blitz Hellion

Trample, haste
At the beginning of the end step, Blitz Hellion's owner shuffles it into their library.

Terramorphic Expanse

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Godtracker of Jund

Whenever a creature you control with power 5 or greater enters, you may put a +1/+1 counter on Godtracker of Jund.

Forest

Rhox Brute

Gorger Wurm

Devour 1 (As this enters, you may sacrifice any number of creatures. This creature enters with that many +1/+1 counters on it.)

Elvish Visionary

When Elvish Visionary enters, draw a card.

Valley Rannet

Mountaincycling {2}, forestcycling {2} ({2}, Discard this card: Search your library for a Mountain or Forest card, reveal it, put it into your hand, then shuffle.)

Colossal Might

Target creature gets +4/+2 and gains trample until end of turn.

Rockslide Elemental

First strike
Whenever another creature dies, you may put a +1/+1 counter on Rockslide Elemental.

Sangrite Surge

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

Dragon Fodder

Create two 1/1 red Goblin creature tokens.

Gluttonous Slime

Flash
Devour 1 (As this enters, you may sacrifice any number of creatures. This creature enters with that many +1/+1 counters on it.)

Vengeful Rebirth

Return target card from your graveyard to your hand. If you return a nonland card to your hand this way, Vengeful Rebirth deals damage equal to that card's mana value to any target.
Exile Vengeful Rebirth.