Inside each ball is liquid latex which makes the magic happen when you squeeze it. Be careful you don’t pierce the ball with your fingernails or any other sharp object lest you be left with a puddle of neon colored goo.

Staphylococcus comes from the Greek words “staphyle” and “kokkos” meaning “a bunch of grapes”. If you squeeze our Infectious Disease Stress Balls, you’ll get a very nasty cluster of pustules, much like a bunch of grapes. Grapes full of orange pus.

This is strangely mesmerizing…

Available from Think Geek. Pretty cheap, too.