Mammoth Spider

Reach (This creature can block creatures with flying.)

Overcome

Creatures you control get +2/+2 and gain trample until end of turn. (Each of those creatures can deal excess combat damage to the player or planeswalker it's attacking.)

Canopy Spider

Aggressive Mammoth

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

Rabid Bite

Target creature you control deals damage equal to its power to target creature you don't control.

Plummet

Centaur Courser

Forest

Prized Unicorn

All creatures able to block Prized Unicorn do so.

Oakenform

Enchant creature
Enchanted creature gets +3/+3.

Titanic Growth

Target creature gets +4/+4 until end of turn.

Woodland Mystic

Bristling Boar

Bristling Boar can't be blocked by more than one creature.

Frilled Sandwalla

{1}{G}: Frilled Sandwalla gets +2/+2 until end of turn. Activate only once each turn.