Old-Growth Troll

Trample
When Old-Growth Troll dies, if it was a creature, return it to the battlefield. It's an Aura enchantment with enchant Forest you control and "Enchanted Forest has '{T}: Add {G}{G}' and '{1}, {T}, Sacrifice this land: Create a tapped 4/4 green Troll Warrior creature token with trample.'"

Charnel Troll

Trample
At the beginning of your upkeep, exile a creature card from your graveyard. If you do, put a +1/+1 counter on Charnel Troll. Otherwise, sacrifice it.
{B}{G}, Discard a creature card: Put a +1/+1 counter on Charnel Troll.

Feasting Troll King

Vigilance, trample
When Feasting Troll King enters the battlefield, if you cast it from your hand, create three Food tokens. (They're artifacts with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")
Sacrifice three Foods: Return Feasting Troll King from your graveyard to the battlefield. Activate only during your turn.

Varolz, the Scar-Striped

Each creature card in your graveyard has scavenge. The scavenge cost is equal to its mana cost. (Exile a creature card from your graveyard and pay its mana cost: Put a number of +1/+1 counters equal to that card's power on target creature. Scavenge only as a sorcery.)
Sacrifice another creature: Regenerate Varolz, the Scar-Striped.

Troll Ascetic

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

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.

Challenger Troll

Each creature you control with power 4 or greater can't be blocked by more than one creature.

Mossbridge Troll

If Mossbridge Troll would be destroyed, regenerate it.
Tap any number of untapped creatures you control other than Mossbridge Troll with total power 10 or greater: Mossbridge Troll gets +20/+20 until end of turn.

Gluttonous Troll

Trample
When Gluttonous Troll enters the battlefield, create a number of Food tokens equal to the number of opponents you have. (Food tokens are artifacts with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")
{1}{G}, Sacrifice another nonland permanent: Gluttonous Troll gets +2/+2 until end of turn.

Clackbridge Troll

Trample, haste
When Clackbridge Troll enters the battlefield, target opponent creates three 0/1 white Goat creature tokens.
At the beginning of combat on your turn, any opponent may sacrifice a creature. If a player does, tap Clackbridge Troll, you gain 3 life, and you draw a card.

Cudgel Troll

{G}: Regenerate Cudgel Troll. (The next time this creature would be destroyed this turn, it isn't. Instead tap it, remove all damage from it, and remove it from combat.)