Cheapest priced copy (Return to Ravnica): $0.35 at Card Kingdom, near mint, their price list as of .
Hellhole Flailer 
Creature — Ogre Warrior · 3/2 · Uncommon · Return to Ravnica · #167
Unleash (You may have this creature enter with a +1/+1 counter on it. It can't block as long as it has a +1/+1 counter on it.)
{2}{B}{R}, Sacrifice this creature: It deals damage equal to its power to target player or planeswalker.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Return to Ravnica | 167 | Uncommon | $0.35 | $0.49 |
5 rulings from Wizards of the Coast
- 1 October 2012The damage dealt by the last ability is equal to Hellhole Flailer's power when it was last on the battlefield. For example, if it had a +1/+1 counter on it, it will deal 4 damage.
- 15 April 2013The unleash ability applies no matter where the creature is entering the battlefield from.
- 15 April 2013Putting a +1/+1 counter on a creature with unleash that's already blocking won't remove it from combat. It will continue to block.
- 15 April 2013You make the choice to have the creature with unleash enter the battlefield with a +1/+1 counter or not as it's entering the battlefield. At that point, it's too late for a player to respond to the creature spell by trying to counter it, for example.
- 15 April 2013A creature with unleash can't block if it has any +1/+1 counter on it, not just one put on it by the unleash ability.