From Valve Developer Community
This entity is a spawn point for a chicken. Should be placed at least 64 units away from each other and surrounding walls. This entity requires a Navigation Mesh to function properly. See also: Pet Population in info_map_parameters.
- Pitch Yaw Roll (Y Z X) (angles)
- This entity's orientation in the world. Pitch is rotation around the Y axis, yaw is the rotation around the Z axis, roll is the rotation around the X axis.