Cheapest priced copy (Marvel Super Heroes Commander): $0.35 at Card Kingdom, near mint, their price list as of .
Beast Mode 
Instant · Common · Marvel Super Heroes Commander · #713
Teamwork 1 (As an additional cost to cast this spell, you may tap any number of creatures you control with total power 1 or more.)
Target creature gets +2/+2 and gains trample until end of turn. Also put a +1/+1 counter on that creature if this spell was cast using teamwork.
Legal inCommanderLegacyVintagePauper
Not legal inBrawlStandardPioneerModern
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Marvel Super Heroes Commander | 713 | Common | $0.35 | $0.49 |