Mirari's Wake

Creatures you control get +1/+1.
Whenever you tap a land for mana, add one mana of any type that land produced.

Johan

At the beginning of combat on your turn, you may have Johan gain "Johan can't attack" until end of combat. If you do, attacking doesn't cause creatures you control to tap this combat if Johan is untapped.

Heartbeat of Spring

Whenever a player taps a land for mana, that player adds one mana of any type that land produced.

Overabundance

Whenever a player taps a land for mana, that player adds one mana of any type that land produced, and Overabundance deals 1 damage to the player.

Managorger Hydra

Trample
Whenever a player casts a spell, put a +1/+1 counter on Managorger Hydra.

Pathbreaker Ibex

Whenever Pathbreaker Ibex attacks, creatures you control gain trample and get +X/+X until end of turn, where X is the greatest power among creatures you control.

Taurean Mauler

Changeling (This card is every creature type.)
Whenever an opponent casts a spell, you may put a +1/+1 counter on this creature.

Mana Flare

Zopandrel, Hunger Dominus

Reach
At the beginning of each combat, double the power and toughness of each creature you control until end of turn.
{G/P}{G/P}, Sacrifice two other creatures: Put an indestructible counter on Zopandrel, Hunger Dominus. ({G/P} can be paid with either {G} or 2 life.)

Gisela, Blade of Goldnight

Flying, first strike
If a source would deal damage to an opponent or a permanent an opponent controls, that source deals double that damage to that player or permanent instead.
If a source would deal damage to you or a permanent you control, prevent half that damage, rounded up.

Unnatural Growth

At the beginning of each combat, double the power and toughness of each creature you control until end of turn.

Kalonian Hydra

Trample
Kalonian Hydra enters with four +1/+1 counters on it.
Whenever Kalonian Hydra attacks, double the number of +1/+1 counters on each creature you control.