Blossoming Defense

Target creature you control gets +2/+2 and gains hexproof until end of turn.

Royal Treatment

Target creature you control gains hexproof until end of turn. Create a Royal Role token attached to that creature. (If you control another Role on it, put that one into the graveyard. Enchanted creature gets +1/+1 and has ward {1}.)

Forest

Groundswell

Target creature gets +2/+2 until end of turn.
Landfall — If you had a land enter the battlefield under your control this turn, that creature gets +4/+4 until end of turn instead.

Glistener Elf

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Blighted Agent

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Blighted Agent can't be blocked.

Spell Pierce

Counter target noncreature spell unless its controller pays {2}.

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.

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.")

Distortion Strike

Target creature gets +1/+0 until end of turn and can't be blocked this turn.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Mutagenic Growth

({G/P} can be paid with either {G} or 2 life.)
Target creature gets +2/+2 until end of turn.

Island

Might of Old Krosa

Target creature gets +2/+2 until end of turn. If you cast this spell during your main phase, that creature gets +4/+4 until end of turn instead.