Shape of the Wiitigo

Enchant creature
When Shape of the Wiitigo enters, put six +1/+1 counters on enchanted creature.
At the beginning of your upkeep, put a +1/+1 counter on enchanted creature if it attacked or blocked since your last upkeep. Otherwise, remove a +1/+1 counter from it.

Fangren Firstborn

Whenever Fangren Firstborn attacks, put a +1/+1 counter on each attacking creature.

Brontotherium

Trample
Provoke (Whenever this creature attacks, you may have target creature defending player controls untap and block it if able.)

Argothian Wurm

Trample
When Argothian Wurm enters, any player may sacrifice a land of their choice. If a player does, put Argothian Wurm on top of its owner's library.

Forest

Loxodon Warhammer

Equipped creature gets +3/+0 and has trample and lifelink.
Equip {3}

Copperhoof Vorrac

Copperhoof Vorrac gets +1/+1 for each untapped permanent your opponents control.

Fangren Pathcutter

Whenever Fangren Pathcutter attacks, attacking creatures gain trample until end of turn.

Naturalize

Rancor

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

Llanowar Elves

Blanchwood Armor

Enchant creature
Enchanted creature gets +1/+1 for each Forest you control.

Priest of Titania

{T}: Add {G} for each Elf on the battlefield.

Gaea's Embrace

Enchant creature
Enchanted creature gets +3/+3 and has trample.
{G}: Regenerate enchanted creature.

Giant Growth

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

Emperor Crocodile

When you control no other creatures, sacrifice Emperor Crocodile.

Eternal Witness

When Eternal Witness enters, you may return target card from your graveyard to your hand.

Mask of Memory

Whenever equipped creature deals combat damage to a player, you may draw two cards. If you do, discard a card.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Predator's Strike

Target creature gets +3/+3 and gains trample until end of turn. (It can deal excess combat damage to the player or planeswalker it's attacking.)

Fyndhorn Elder

Uktabi Wildcats

Uktabi Wildcats's power and toughness are each equal to the number of Forests you control.
{G}, Sacrifice a Forest: Regenerate Uktabi Wildcats.

Vernal Bloom

Whenever a Forest is tapped for mana, its controller adds an additional {G}.

Yavimaya Elder

When Yavimaya Elder dies, you may search your library for up to two basic land cards, reveal them, put them into your hand, then shuffle.
{2}, Sacrifice Yavimaya Elder: Draw a card.