Hookhand Mariner // Riphook Raider (VOW-203) - Innistrad: Crimson Vow: (Double Faced Transform)

Daybound (If a player casts no spells during their own turn, it becomes night next turn.)

Riphook Raider can't be blocked by creatures with power 2 or less.
Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)