Territorial Witchstalker

Defender
At the beginning of combat on your turn, if you control a creature with power 4 or greater, this creature gets +1/+0 until end of turn and can attack this turn as though it didn't have defender.

Feed the Clan

You gain 5 life.
Ferocious — You gain 10 life instead if you control a creature with power 4 or greater.

Frontier Mastodon

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

Ornery Dilophosaur

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

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.

Whisperer of the Wilds

{T}: Add {G}.
Ferocious — {T}: Add {G}{G}. Activate only if you control a creature with power 4 or greater.

Kronch Wrangler

Trample
Whenever a creature you control with power 4 or greater enters, put a +1/+1 counter on this creature.

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.

Ent's Fury

Put a +1/+1 counter on target creature you control if its power is 4 or greater. Then that creature gets +1/+1 until end of turn and fights target creature you don't control.

Boulderbranch Golem

Prototype {3}{G} — 3/3 (You may cast this spell with different mana cost, color, and size. It keeps its abilities and types.)
When this creature enters, you gain life equal to its power.

Territorial Boar

Whenever a creature you control with power 4 or greater enters, this creature gets +1/+1 and gains vigilance until end of turn.

Vine Snare

Prevent all combat damage that would be dealt this turn by creatures with power 4 or less.