Crookclaw Transmuter

Flash
Flying
When Crookclaw Transmuter enters, switch target creature's power and toughness until end of turn.

Time Spiral Remastered

Flash
Flying
When Crookclaw Transmuter enters the battlefield, switch target creature's power and toughness until end of turn.

Jumpstart

Conspiracy

Flash (You may cast this spell any time you could cast an instant.)
Flying
When Crookclaw Transmuter enters the battlefield, switch target creature's power and toughness until end of turn.

Time Spiral

Flash (You may play this spell any time you could play an instant.)
Flying
When Crookclaw Transmuter comes into play, switch target creature's power and toughness until end of turn.

Because 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.

Effects 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.

Switching 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.