Sims 3 Pets: How to get a unicorn?

Some of that is complete rubbish! Like the fact that if you don't have the "animal lover" trait the glow won't appear! It for sure does! 

Another way to not get the rejection is to be friends (or is it best friends?) with all the pets in your household. (Or is could be best friends with 10 animals?) Not sure...

Enjoy playing with your unicorn!