Drowsing Tyrannodon

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

Thriving Grove

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

Challenger Troll

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

Garruk's Uprising

When this enchantment enters, if you control a creature with power 4 or greater, draw a card.
Creatures you control have trample. (Each of those creatures can deal excess combat damage to the player or planeswalker it's attacking.)
Whenever a creature you control with power 4 or greater enters, draw a card.

Bannerhide Krushok

Trample
Reinforce 2—{1}{G} ({1}{G}, Discard this card: Put two +1/+1 counters on target creature.)
Scavenge {5}{G}{G} ({5}{G}{G}, Exile this card from your graveyard: Put a number of +1/+1 counters equal to this card's power on target creature. Scavenge only as a sorcery.)

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.

Forest

Goreclaw, Terror of Qal Sisma

Creature spells you cast with power 4 or greater cost {2} less to cast.
Whenever Goreclaw attacks, each creature you control with power 4 or greater gets +1/+1 and gains trample until end of turn.

Nessian Hornbeetle

At the beginning of combat on your turn, if you control another creature with power 4 or greater, put a +1/+1 counter on this creature.

Alpine Grizzly

Frontier Mastodon

Ferocious — This creature enters with a +1/+1 counter on it if you control a creature with power 4 or greater.

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.

Bristling Boar

This creature can't be blocked by more than one creature.

Rosethorn Halberd

When this Equipment enters, attach it to target non-Human creature you control.
Equipped creature gets +2/+1.
Equip {5} ({5}: Attach to target creature you control. Equip only as a sorcery.)