Breakneck Rider // Neck Breaker (SOI-147) - Shadows over Innistrad: (Double Faced Transform)

At the beginning of each upkeep, if no spells were cast last turn, transform Breakneck Rider.

Attacking creatures you control get +1/+0 and have trample.
At the beginning of each upkeep, if a player cast two or more spells last turn, transform Neck Breaker.