Cheapest priced copy (Commander 2015): $0.35 at Card Kingdom, near mint, their price list as of .
Plaxmanta 
Creature — Beast · 2/2 · Uncommon · Commander 2015 · #100
Flash
When this creature enters, creatures you control gain shroud until end of turn. (They can't be the targets of spells or abilities.)
When this creature enters, sacrifice it unless {G} was spent to cast it.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
3 printings · $0.35 to $2.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Commander 2015 | 100 | Uncommon | $0.35 | — |
| Dissension | 29 | Uncommon | $0.39 | $2.99 |
| The List | DIS-29 | Uncommon | $0.35 | — |
One ruling from Wizards of the Coast
- 1 May 2006If this enters in a way other than announcing it as a spell, then the appropriate mana can't have been paid, and you'll have to sacrifice it.