Giant Growth

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

Rampaging Rendhorn

Riot (This creature enters with your choice of a +1/+1 counter or haste.)

Mammoth Spider

Reach (This creature can block creatures with flying.)

Aggressive Mammoth

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Other creatures you control have trample.

Llanowar Elves

Vigorspore Wurm

Undergrowth — When Vigorspore Wurm enters, target creature gains vigilance and gets +X/+X until end of turn, where X is the number of creature cards in your graveyard.
Vigorspore Wurm can't be blocked by more than one creature.

Forest

Circuitous Route

Search your library for up to two basic land cards and/or Gate cards, put them onto the battlefield tapped, then shuffle.

Wrecking Beast

Riot (This creature enters with your choice of a +1/+1 counter or haste.)
Trample

Greenwood Sentinel

Vigilance (Attacking doesn't cause this creature to tap.)

District Guide

When District Guide enters, you may search your library for a basic land card or Gate card, reveal it, put it into your hand, then shuffle.

Open the Gates

Search your library for a basic land card or Gate card, reveal it, put it into your hand, then shuffle.