Gyftrot is a paranoid and irritated monster. This behavior arose due to some other monsters (likely kids) decorating them without their consent. When someone meets Gyftrot, they get very irritated from their presence since they might have a "youthful demeanor." Defying this, if someone undecorates Gyftrot, they would be forever grateful and start to trust them. However, if one would decorate them afterward, this comes as a surprise attack and crushes Gyftrot's trust for them, He likes gifts.