Dancing Hoskuld
Deity
All that can be done with "just" XML. Get yourself an XML editor or even one of the Notepad equavalents that does simple syntax checks.
A good one to start would probably be cheetahs as they like people well adults, children they find delicious
. Make a copy of the tamed animal unit infos but only keep one animal type in it eg lion, then rename all _LION to _CHEETAH add the cheetah to the unit class file and it is done!
Of course you still need to balance with C2C and decide if we should have a new building Cheetah Trainer
A good one to start would probably be cheetahs as they like people well adults, children they find delicious

Of course you still need to balance with C2C and decide if we should have a new building Cheetah Trainer