Become Immense

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Target creature gets +6/+6 until end of turn.

Nantuko Mentor

{2}{G}, {T}: Target creature gets +X/+X until end of turn, where X is that creature's power.

Sylvan Might

Target creature gets +2/+2 and gains trample until end of turn.
Flashback {2}{G}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Invigorate

If you control a Forest, rather than pay this spell's mana cost, you may have an opponent gain 3 life.
Target creature gets +4/+4 until end of turn.

Monstrous Growth

Target creature gets +4/+4 until end of turn.

Primal Boost

Target creature gets +4/+4 until end of turn.
Cycling {2}{G} ({2}{G}, Discard this card: Draw a card.)
When you cycle Primal Boost, you may have target creature get +1/+1 until end of turn.

Might of Oaks

Target creature gets +7/+7 until end of turn.

Dense Foliage

Creatures can't be the targets of spells.

Giant Growth

Target creature gets +3/+3 until end of turn.

Accelerated Mutation

Target creature gets +X/+X until end of turn, where X is the highest mana value among permanents you control.

Berserk

Cast this spell only before the combat damage step.
Target creature gains trample and gets +X/+0 until end of turn, where X is its power. At the beginning of the next end step, destroy that creature if it attacked this turn.

Power Matrix

{T}: Target creature gets +1/+1 and gains flying, first strike, and trample until end of turn.