Cheapest priced copy (Duskmourn: House of Horror): $2.29 at Card Kingdom, near mint, their price list as of .
Silent Hallcreeper 
Enchantment Creature — Horror · 1/1 · Rare · Duskmourn: House of Horror · #345
This creature can't be blocked.
Whenever this creature deals combat damage to a player, choose one that hasn't been chosen —
• Put two +1/+1 counters on this creature.
• Draw a card.
• This creature becomes a copy of another target creature you control.
Legal inCommanderBrawlStandardPioneerModernLegacyVintage
Not legal inPauper
4 printings · $2.29 to $6.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Duskmourn: House of Horror | 72 | Rare | $2.29 | $2.99 |
| Duskmourn: House of Horror | 345 | Rare | $2.99 | $6.99 |
| Duskmourn: House of Horror Promos | 72p | Rare | $2.79 | $3.99 |
| Duskmourn: House of Horror Promos | 72s | Rare | — | $4.99 |
7 rulings from Wizards of the Coast
- 20 September 2024Silent Hallcreeper copies exactly what was printed on the target creature and nothing else (unless that creature is copying something else or is a token; see below). It doesn't copy whether that creature is tapped or untapped, whether it has any counters on it or Auras and Equipment attached to it, or any non-copy effects that have changed its power, toughness, types, color, and so on.
- 20 September 2024The phrase "that hasn't been chosen" refers only to that specific Silent Hallcreeper. If Silent Hallcreeper leaves the battlefield and then returns to the battlefield later, it will be a new object with no memory of the modes that were chosen when it was last on the battlefield.
- 20 September 2024If the copied creature is a token, Silent Hallcreeper copies the original characteristics of that token as stated by the effect that created that token.
- 20 September 2024When Silent Hallcreeper becomes a copy of the target creature, it's neither entering nor leaving the battlefield. Any enters-the-battlefield or leaves-the-battlefield abilities won't trigger.
- 20 September 2024If the third mode is chosen for Silent Hallcreeper's last ability but the target creature is an illegal target as the ability tries to resolve, it won't resolve and none of its effects will happen.
- 20 September 2024While Silent Hallcreeper is a copy of another creature, it won't have any of its previous abilities.
- 20 September 2024If the copied creature is copying something else, then Silent Hallcreeper becomes a copy of whatever that creature copied.