Spectral Hunt-Caller

{5}{G}: Creatures you control get +1/+1 and gain trample until end of turn.

Gaea's Protector

Gaea's Protector must be blocked if able.

Forest

Roar of Challenge

All creatures able to block target creature this turn do so.
Ferocious — That creature gains indestructible until end of turn if you control a creature with power 4 or greater.

Drowsing Tyrannodon

Defender (This creature can't attack.)
As long as you control a creature with power 4 or greater, Drowsing Tyrannodon can attack as though it didn't have defender.

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.

Giant Ladybug

Reach
When Giant Ladybug enters, you may search your library for a basic land card, reveal it, then shuffle and put that card on top.

Challenger Troll

Each creature you control with power 4 or greater can't be blocked by more than one creature.

Colossal Majesty

At the beginning of your upkeep, if you control a creature with power 4 or greater, draw a card.

Ornery Dilophosaur

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Whenever Ornery Dilophosaur attacks, if you control a creature with power 4 or greater, Ornery Dilophosaur gets +2/+2 until end of turn.

Thriving Grove

Thriving Grove enters tapped. As it enters, choose a color other than green.
{T}: Add {G} or one mana of the chosen color.

Rampaging Growth

Search your library for a basic land card, put it onto the battlefield, then shuffle. Until end of turn, that land becomes a 4/3 Insect creature with reach and haste. It's still a land.

Rhonas the Indomitable

Deathtouch, indestructible
Rhonas the Indomitable can't attack or block unless you control another creature with power 4 or greater.
{2}{G}: Another target creature gets +2/+0 and gains trample until end of turn.

Savage Punch

Target creature you control fights target creature you don't control.
Ferocious — The creature you control gets +2/+2 until end of turn before it fights if you control a creature with power 4 or greater.