There are many different kinds of fun balls, from emoji balls to oversized and weighted ping pong balls like these from Killerspin. This package of 4 easily sightable balls has 2x 55mm balls and 2x 44mm balls that weigh more than regular ones.
You can practice ping pong with these, use them to play catch, give them to a dog or cat to play with, or anything in between. However, the main use is meant to play table tennis, and the best use comes from playing outdoors. The wind really doesn’t affect these balls, so if you like playing outdoor table tennis but live in a windy area, these balls might be the perfect choice for you.
The only con is that the price per ball is considerably higher when compared to other balls; however, these are special ones, and you only get 4, so it’s not so expensive.