FOILCheapest priced copy (Battle for Zendikar): $0.69 at Card Kingdom, near mint, their price list as of .
Guardian of Tazeem 
Creature — Sphinx · 4/5 · Rare · Battle for Zendikar Promos · #78s
Flying
Landfall — Whenever a land you control enters, tap target creature an opponent controls. If that land is an Island, that creature doesn't untap during its controller's next untap step.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
2 printings · $0.69 to $3.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Battle for Zendikar | 78 | Rare | $0.69 | $1.49Out of stock |
| Battle for Zendikar Promos | 78s | Rare | — | $3.49Out of stock |
5 rulings from Wizards of the Coast
- 25 August 2015The ability tracks the creature, but not its controller. If the creature changes controllers before its first controller's next untap step has come around, then it won't untap during its new controller's next untap step.
- 25 August 2015Guardian of Tazeem's landfall ability can target a creature that's already tapped. If the land that caused it to trigger was an Island, that creature won't untap during its controller's next untap step.
- 8 November 2024A landfall ability triggers whenever a land you control enters for any reason. It triggers whenever you play a land, as well as whenever a spell or ability puts a land onto the battlefield under your control.
- 8 November 2024A landfall ability doesn't trigger if a permanent already on the battlefield becomes a land.
- 8 November 2024Whenever a land you control enters, each landfall ability of the permanents you control will trigger. You can put them on the stack in any order. The last ability you put on the stack will be the first one to resolve (As a result, you can have those abilities resolve in the order of your choosing.).