Cheapest priced copy (Chronicles): $0.35 at Card Kingdom, near mint, their price list as of .
Transmutation 
Instant · Common · Legends · #123
Switch target creature's power and toughness until end of turn.
Legal inCommanderLegacyVintagePauper
Not legal inBrawlStandardPioneerModern
3 printings · $0.35 to $1.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Chronicles Foreign Black Border | 40 | Common | — | — |
| Chronicles | 40 | Common | $0.35 | — |
| Legends | 123 | Common | $1.49 | — |
4 rulings from Wizards of the Coast
- 1 November 2005Note that the wording "Effects that alter the creature's power alter its toughness instead, and vice versa, this turn" has been removed.
- 19 March 2021Effects that switch a creature's power and toughness apply after all other effects, regardless of when those effects began to apply. For instance, if you target a 1/2 creature then give it +2/+0 later in the turn, it's a 2/3 creature, not a 4/1 creature.
- 19 March 2021Because damage remains marked on a creature until the damage is removed as the turn ends, nonlethal damage dealt to a creature may become lethal if you switch its power and toughness during that turn.
- 19 March 2021Switching a creature's power and toughness twice (or any even number of times) effectively returns the creature to the power and toughness it had before any switches.