Roughshod Mentor

Green creatures you control have trample.

Loxodon Warhammer

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

Duskdale Wurm

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)

Forest

Civic Wayfinder

When this creature enters, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Troll Ascetic

Hexproof (This creature can't be the target of spells or abilities your opponents control.)
{1}{G}: Regenerate this creature.

Molimo, Maro-Sorcerer

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Molimo's power and toughness are each equal to the number of lands you control.

Natural Spring

Wurm's Tooth

Whenever a player casts a green spell, you may gain 1 life.

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Blanchwood Armor

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

Verdant Force

At the beginning of each upkeep, create a 1/1 green Saproling creature token.

Spined Wurm

River Boa

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
{G}: Regenerate this creature.

Giant Growth

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

Vigor

Trample
If damage would be dealt to another creature you control, prevent that damage. Put a +1/+1 counter on that creature for each 1 damage prevented this way.
When Vigor is put into a graveyard from anywhere, shuffle it into its owner's library.

Howl of the Night Pack

Create a 2/2 green Wolf creature token for each Forest you control.

Overrun

Creatures you control get +3/+3 and gain trample until end of turn. (Each of those creatures can deal excess combat damage to the player or planeswalker it's attacking.)