This is a "stress ball". It's a squeezy ball made of some type of solid, sort of soft foam. You can squish it & that's supposed to relieve stress. The design is nice & bright, with a big yellow star & all-over graphics. It has neo-classic art for Sonic, Amy, Knuckles, Eggman & Tails. (Tails is hidden in the corner there) The other side of the ball has just

Sonic & the classic logo. This was made by PMS (the somewhat unforunately named company that produces carnival prizes as well) 
Stress ball care: If you aquire a collectible stress ball, it's good to put it inside of a case & not squeeze it after it is a few years old. The exterior designs on this type of ball have been known to flake with age, sometimes.