{1}{G}: This creature gets +2/+2 until end of turn. Activate only once each turn.
At the beginning of each upkeep, if no spells were cast last turn, transform this creature.

{3}{G}: This creature gets +4/+4 until end of turn. Activate only once each turn.
At the beginning of each upkeep, if a player cast two or more spells last turn, transform this creature.