How to lower a pet's happiness so that it will play a toy?

@ Sincere Malerias Clawed Glove will randomly lower happiness, hunger, or hp to 0 of a random pet each time you use it while battling. Just let me know if you need to borrow it.

Also, the minion raises the pet's happiness to 10, so it should be removed as well.

(Edited to clarify a random pet. Also found out that the MCG doesn't affect the pet that used it during battle.)

yes could I please borrow it? Thanks

The Malerias Clawed Glove is here: Trade Lot

Also, if you haven't unlocked Gunter, you should do it together: https://subeta.net/forums.php/read/878860/Complete-List-of-Unlockable-Challengers

Trade Lot

If the pet has a minion that keeps it's happiness full. Whoops just saw it was mentioned earlier. My bad!

If your pet is in the Resort or Inn they will also stay happy, minion or no. The MCG is tier 6, so in order to use it at least one of your pets must be that strong. It is possible if you're quick after fighting to find a pet in either hotel in an unhappy state from an MCG battle, but not for long.

Another thing you can do if you have the spare pet slot is adopt a pet from Adopt R Us. They tend to be sad if they've been in there for very long. This works if you want to play with a toy but otherwise don't care