In KMS, all characters can use three pets, without need for Pet Snack. So, over there it makes sense to give Pink Bean three pets.
The event was copied as-is, and nobody at Nexon realized that three pets and no Pet Snack don't work in GMS.
The sadder thing is that this is the third time we are getting this event. People complained about the three pets the last two times, too. Nothing was changed.
I've forwarded the issue again. Hopefully next time it can be fixed.
Remember the cute Tamable Hog, the badass Silvermane, and the majestic Red Draco?
Explorers can finally obtain them again.
If you're an Explorer, level 60 or higher, you can talk to Kenta at the Aquarium Zoo to start the quest.