Cheapest priced copy (Mystery Booster 2): $0.99 at Card Kingdom, near mint, their price list as of .
Death's Shadow 
Creature — Avatar · 13/13 · Rare · Worldwake · #57
This creature gets -X/-X, where X is your life total.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
7 printings · $0.99 to $10.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Double Masters | 82 | Rare | $1.29 | $2.49 |
| Mystery Booster 2 | 180 | Rare | $0.99 | $10.99 |
| Modern Masters 2017 | 64 | Rare | $1.29 | $2.49 |
| Store Championships (Diabolos, Guardian Force) | 40 | Rare | — | $5.49 |
| Secret Lair Drop | 474 | Rare | $6.99 | $6.99 |
| Secret Lair Promo | 8 | Rare | $3.99 | $10.99 |
| Worldwake | 57 | Rare | $0.99 | $6.99 |
4 rulings from Wizards of the Coast
- 7 August 2020If your life total is negative, X is considered to be 0.
- 7 August 2020Death's Shadow's ability applies only while Death's Shadow is on the battlefield. In all other zones, its power and toughness are 13.
- 7 August 2020In a Two-Headed Giant game, your life total is your team's life total.
- 7 August 2020The value of X changes as you gain and lose life. It's not locked in as Death's Shadow enters the battlefield.