Cheapest priced copy (Legions): $0.35 at Card Kingdom, near mint, their price list as of .
Mistform Sliver 
Creature — Illusion Sliver · 1/1 · Common · Legions · #46
All Slivers have "{1}: This permanent becomes the creature type of your choice in addition to its other types until end of turn."
Legal inCommanderLegacyVintagePauper
Not legal inBrawlStandardPioneerModern
1 printing · $0.35 to $4.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Legions | 46 | Common | $0.35 | $4.49 |
3 rulings from Wizards of the Coast
- 4 October 2004Unlike most type changing effects, this one adds a creature type instead of replacing existing creature types.
- 1 July 2013Abilities that Slivers grant, as well as power/toughness boosts, are cumulative. However, for some abilities, like flying, having more than one instance of the ability doesn’t provide any additional benefit.
- 1 July 2013If the creature type of a Sliver changes so it’s no longer a Sliver, it will no longer be affected by its own ability. Its ability will continue to affect other Sliver creatures.