These can only be unlocked in Ambition Mode. To welcome the Emperor, you must have completed construction of the Tongquetai.

Animal	How to unlock
Golden Panda	Welcomed Emperor and recruited all allies.
Harrier	Welcomed Emperor and all Facilities fully upgraded.
Hex Mark	Complete 60 consecutive battles.
Red Hare	Complete 90 consecutive battles.
Shadow Runner	Complete 30 consecutive battles.
War Elephant	Complete 100 consecutive battles.