What is the ruling on using Snapchat filters that add light decorations where animal ears would be, a black dot on the nose, and a slight puffiness to the face, and are often used for children?

Fatwa 169799 regarding filters is clear. It indicates that some of them are permissible, such as adding an image of flowers above the head. Therefore, as long as image filters do not involve resemblance to animals and do not alter creation, they are not prohibited.