Homarid

Homarid enters the battlefield with a tide counter on it.
At the beginning of your upkeep, put a tide counter on Homarid.
As long as there is exactly one tide counter on Homarid, it gets -1/-1.
As long as there are exactly three tide counters on Homarid, it gets +1/+1.
Whenever there are four or more tide counters on Homarid, remove all tide counters from it.

Thorn Thallid

At the beginning of your upkeep, put a spore counter on Thorn Thallid.
Remove three spore counters from Thorn Thallid: It deals 1 damage to any target.

Aeolipile

, , Sacrifice Aeolipile: It deals 2 damage to any target.

Night Soil

, Exile two creature cards from a single graveyard: Create a 1/1 green Saproling creature token.

Initiates of the Ebon Hand

: Add . If this ability has been activated four or more times this turn, sacrifice Initiates of the Ebon Hand at the beginning of the next end step.

Merseine

Enchant creature
Merseine enters the battlefield with three net counters on it.
Enchanted creature doesn’t untap during its controller’s untap step if Merseine has a net counter on it.
Pay enchanted creature’s mana cost: Remove a net counter from Merseine. Only the controller of the enchanted creature may activate this ability.

Mindstab Thrull

Whenever Mindstab Thrull attacks and isn’t blocked, you may sacrifice it. If you do, defending player discards three cards.

Goblin War Drums

Creatures you control have menace. (They can’t be blocked except by two or more creatures.)

Brassclaw Orcs

Brassclaw Orcs can’t block creatures with power 2 or greater.

Icatian Skirmishers

First strike; banding (Any creatures with banding, and up to one without, can attack in a band. Bands are blocked as a group. If any creatures with banding you control are blocking or being blocked by a creature, you divide that creature’s combat damage, not its controller, among any of the creatures it’s being blocked by or is blocking.)
Whenever Icatian Skirmishers attacks, all creatures banded with it gain first strike until end of turn.

Righteous Avengers

Plainswalk (This creature can’t be blocked as long as defending player controls a Plains.)

Chains of Mephistopheles

If a player would draw a card except the first one they draw in each of their draw steps, that player discards a card instead. If the player discards a card this way, they draw a card. If the player doesn’t discard a card this way, they mill a card.