Often called "patent leather ball", "elastic ball", etc.
Slime ball toys are often called "patent leather balls", "slime balls", "elastic balls", etc. It is an elastic sphere made of polymer material with a sticky surface and can be as elastic as rubber. Some merchants will also label them with various cute cartoon images to make them more attractive.
Toys generally refer to items that can be played with. Playing with toys is often used as a way of entertaining and educating people in human society.