Electrostatic Infantry

Trample
Whenever you cast an instant or sorcery spell, put a +1/+1 counter on this creature.

Snakeskin Veil

Put a +1/+1 counter on target creature you control. It gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

Mountain

Ilysian Caryatid

{T}: Add one mana of any color. If you control a creature with power 4 or greater, add two mana of any one color instead.

Dragonsguard Elite

Magecraft — Whenever you cast or copy an instant or sorcery spell, put a +1/+1 counter on this creature.
{4}{G}{G}: Double the number of +1/+1 counters on this creature.

Goblin Anarchomancer

Each spell you cast that's red or green costs {1} less to cast.

Forest

Rhythm of the Wild

Creature spells you control can't be countered.
Nontoken creatures you control have riot. (They enter with your choice of a +1/+1 counter or haste.)

Fists of Flame

Draw a card. Until end of turn, target creature gains trample and gets +1/+0 for each card you've drawn this turn. (A creature with trample can deal excess combat damage to the player or planeswalker it's attacking.)

Lead by Example

Support 2. (Put a +1/+1 counter on each of up to two target creatures.)

Stomping Ground

({T}: Add {R} or {G}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Temple of Abandon

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {R} or {G}.

Mirrorwing Dragon

Flying
Whenever a player casts an instant or sorcery spell that targets only this creature, that player copies that spell for each other creature they control that the spell could target. Each copy targets a different one of those creatures.

Impact Tremors

Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.

Zada, Hedron Grinder

Whenever you cast an instant or sorcery spell that targets only Zada, copy that spell for each other creature you control that the spell could target. Each copy targets a different one of those creatures.

Silverfur Partisan

Trample
Whenever a Wolf or Werewolf you control becomes the target of an instant or sorcery spell, create a 2/2 green Wolf creature token.