pf2e.fyi
From Pathfinder Howl of the Wild, which isn't enabled.

Rapid Hybridization

FEAT 14
ARCHETYPE
Activity free action
Archetype Werecreature
Prerequisites Werecreature Dedication
Trigger You roll initiative.

When danger threatens, your instincts kick in, and you can assume a different shape at a moment's notice. You use Change Shape to enter your hybrid shape.

Pathfinder Howl of the WildORC