Cheapest priced copy (Commander 2014): $0.99 at Card Kingdom, near mint, their price list as of .
Frost Titan 
Creature — Giant · 6/6 · Mythic · Secret Lair Drop · #220
Whenever this creature becomes the target of a spell or ability an opponent controls, counter that spell or ability unless its controller pays {2}.
Whenever this creature enters or attacks, tap target permanent. It doesn't untap during its controller's next untap step.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
6 printings · $0.99 to $3.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Commander 2014 | 112 | Mythic | $0.99 | — |
| Magic 2011 | 55 | Mythic | $1.29 | $3.49 |
| Magic 2012 | 55 | Mythic | $0.99 | $2.99 |
| Duels of the Planeswalkers 2012 Promos | 1 | Mythic | — | $2.29 |
| The List | M11-55 | Mythic | $0.99 | — |
| Secret Lair Drop | 220 | Mythic | $2.79 | $3.49 |
4 rulings from Wizards of the Coast
- 15 August 2010Frost Titan’s first ability affects each spell (including Aura spells), activated ability, and triggered ability that’s controlled by an opponent and that Frost Titan becomes a target of.
- 15 August 2010You may target any permanent with Frost Titan’s second ability. It’s okay if that permanent is already tapped.
- 15 August 2010If the permanent affected by Frost Titan’s second ability is untapped at the time that permanent’s controller’s next untap step begins, the last part of Frost Titan’s second ability has no effect.
- 15 August 2010If the permanent affected by Frost Titan’s second ability changes controllers before its old controller’s next untap step, Frost Titan’s second ability will prevent it from being untapped during its new controller’s next untap step.