Cheapest priced copy (Modern Horizons 2): $0.69 at Card Kingdom, near mint, their price list as of .
Carth the Lion 
Legendary Creature — Human Warrior · 3/5 · Rare · Modern Horizons 2 · #418
Whenever Carth enters or a planeswalker you control dies, look at the top seven cards of your library. You may reveal a planeswalker card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.
Planeswalkers' loyalty abilities you activate cost an additional [+1] to activate.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
4 printings · $0.69 to $2.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Modern Horizons 2 | 189 | Rare | $0.69 | $0.99 |
| Modern Horizons 2 | 418 | Rare | $0.99 | $1.49 |
| Modern Horizons 2 | 464 | Rare | $1.79 | $2.49 |
| Modern Horizons 2 Promos | 189s | Rare | — | $0.99Out of stock |
4 rulings from Wizards of the Coast
- 18 June 2021The total cost of a planeswalker's loyalty ability is calculated before any counters are added or removed. If a loyalty ability normally costs [-3] to activate, you do not remove three counters from it and then put one counter on it. You remove two counters at one time when you pay the cost.
- 18 June 2021If you somehow manage to control two Carths (perhaps because of Spark Double), the cost-changing effect is cumulative. In total, loyalty abilities will cost an additional [+2] to activate.
- 18 June 2021If an effect replaces the number of counters that would be placed on a planeswalker, such as that of Vorinclex, Monstrous Raider, that replacement happens only once, at the time payment is made.
- 18 June 2021If a planeswalker's loyalty ability normally has a cost of [+1], Carth's ability makes it cost [+2] instead. A cost of [0] would become [+1], and a cost of [-6] would become [-5].