Primal Bellow

Target creature gets +1/+1 until end of turn for each Forest you control.

Cudgel Troll

{G}: Regenerate Cudgel Troll. (The next time this creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

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.

Regrowth

Return target card from your graveyard to your hand.

Sporeback Troll

Graft 2 (This creature enters with two +1/+1 counters on it. Whenever another creature enters, you may move a +1/+1 counter from this creature onto it.)
{1}{G}: Regenerate target creature with a +1/+1 counter on it.

Thrun, the Last Troll

This spell can't be countered.
Hexproof (This creature can't be the target of spells or abilities your opponents control.)
{1}{G}: Regenerate Thrun, the Last Troll.

Forest

Barkhide Troll

Barkhide Troll enters with a +1/+1 counter on it.
{1}, Remove a +1/+1 counter from Barkhide Troll: Barkhide Troll gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

Trollbred Guardian

{2}{G}: Adapt 2. (If this creature has no +1/+1 counters on it, put two +1/+1 counters on it.)
Each creature you control with a +1/+1 counter on it has trample.

Alpha Authority

Enchant creature
Enchanted creature has hexproof and can't be blocked by more than one creature.

Skyshroud Troll

Undercity Troll

Renown 1 (When this creature deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.)
{2}{G}: Regenerate Undercity Troll. (The next time this creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Rampant Growth

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