Cheapest priced copy (Foundations): $4.49 at Card Kingdom, foil, near mint, their price list as of .
Massacre Wurm 
Creature — Phyrexian Wurm · 6/5 · Mythic · Duskmourn: House of Horror Commander · #147
When this creature enters, creatures your opponents control get -2/-2 until end of turn.
Whenever a creature an opponent controls dies, that player loses 2 life.
Legal inCommanderBrawlStandardPioneerModernLegacyVintage
Not legal inPauper
11 printings · $4.49 to $24.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Duskmourn: House of Horror Commander | 147 | Mythic | $6.99 | — |
| Foundations | 714 | Mythic | — | $4.49 |
| Foundations | 754 | Mythic | — | — |
| Jumpstart 2022 | 441 | Mythic | $6.99 | — |
| Core Set 2021 | 114 | Mythic | $7.49 | $6.99 |
| Core Set 2021 | 316 | Mythic | $14.99 | $24.99 |
| Mirrodin Besieged | 46 | Mythic | $8.49 | $22.99 |
| Murders at Karlov Manor Commander | 130 | Mythic | $6.99 | — |
| March of the Machine Commander | 256 | Mythic | $6.99 | — |
| Core Set 2021 Promos | 114p | Mythic | $11.99 | $13.99 |
| Core Set 2021 Promos | 114s | Mythic | — | $15.99 |
4 rulings from Wizards of the Coast
- 23 June 2020Massacre Wurm's triggered ability triggers if a creature an opponent controls dies for any reason, including from its first ability reducing its toughness to 0, as long as Massacre Wurm remains on the battlefield.
- 23 June 2020Massacre Wurm's first ability affects only creatures your opponents control at the time it resolves. Creatures they begin to control later in the turn won't get -2/-2.
- 23 June 2020If your life total is brought to 0 or less at the same time that a creature an opponent controls is dealt lethal damage, you lose the game before Massacre Wurm's last ability goes on the stack.
- 23 June 2020If a creature an opponent controls dies at the same time as Massacre Wurm, Massacre Wurm's last ability triggers for that creature.