It is exclusive to Naesala.
Raven King Beak
Grants Spd+3. If unit's Spd > foe's Spd, deals damage equal to 70% of difference between stats. (Maximum bonus of +7 damage. Combos with Phantom Spd.) At start of turn, if unit is adjacent to only beast or dragon allies or if unit is not adjacent to any ally, unit transforms (otherwise, unit reverts). If unit transforms, unit can move 1 extra space. (That turn only. Does not stack.) If unit transforms, grants Atk+2.