Syr Faren, the Hengehammer

Whenever Syr Faren attacks, another target attacking creature gets +X/+X until end of turn, where X is Syr Faren's power.

Rancor

Enchant creature
Enchanted creature gets +2/+0 and has trample.
When this Aura is put into a graveyard from the battlefield, return it to its owner's hand.

Champion of Lambholt

Creatures with power less than this creature's power can't block creatures you control.
Whenever another creature you control enters, put a +1/+1 counter on this creature.

Scale Up

Until end of turn, target creature you control becomes a green Wurm with base power and toughness 6/4.
Overload {4}{G}{G} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Primal Bellow

Target creature gets +1/+1 until end of turn for each Forest you control.

Tyvar, the Pummeler

Tap another untapped creature you control: Tyvar gains indestructible until end of turn. Tap it.
{3}{G}{G}: Creatures you control get +X/+X until end of turn, where X is the greatest power among creatures you control.

Wild Beastmaster

Whenever this creature attacks, each other creature you control gets +X/+X until end of turn, where X is this creature's power.

Aspect of Hydra

Target creature gets +X/+X until end of turn, where X is your devotion to green. (Each {G} in the mana costs of permanents you control counts toward your devotion to green.)