Cheapest priced copy (Planeshift): $0.39 at Card Kingdom, near mint, their price list as of .
Thunderscape Familiar 
Creature — Kavu · 1/1 · Common · Planeshift · #76
First strike
Black spells and green spells you cast cost {1} less to cast.
Legal inCommanderLegacyVintagePauper
Not legal inBrawlStandardPioneerModern
1 printing · $0.39 to $10.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Planeshift | 76 | Common | $0.39 | $10.99 |
7 rulings from Wizards of the Coast
- 4 October 2004If a spell is both black and green, you pay {1} less, not {2} less.
- 4 October 2004The generic X cost is still considered generic even if there is a requirement that a specific color be used for it. For example, “only black mana can be spent this way”. This distinction is important for effects which reduce the generic portion of a spell’s cost.
- 4 October 2004The lower cost is not optional like with some other cost reducers.
- 4 October 2004If this card is sacrificed to pay part of a spell’s cost, the cost reduction still applies.
- 4 October 2004This can lower the cost to zero, but not below zero.
- 4 October 2004Can never affect the colored part of the cost.
- 4 October 2004The effect is cumulative.