Cheapest priced copy (The List): $4.99 at Card Kingdom, near mint, their price list as of .
Hedron Crab 
Creature — Crab · 0/2 · Uncommon · Zendikar · #47
Landfall — Whenever a land you control enters, target player mills three cards. (They put the top three cards of their library into their graveyard.)
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
4 printings · $4.99 to $29.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| The List | ZEN-47 | Uncommon | $4.99 | — |
| Secret Lair Drop | 1430 | Rare | $24.99 | $29.99 |
| Tarkir: Dragonstorm Commander | 155 | Uncommon | $4.99 | — |
| Zendikar | 47 | Uncommon | $5.49 | $27.99 |
3 rulings from Wizards of the Coast
- 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.).
- 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.