Today is a good day! It’s Fun at Work day!
Of course, today is also April Fools Day- probably by design. And yes, harmless pranks might be a good way to have a little fun, but it’s far from the only way.
You could bring in treats. You could tell a couple work appropriate jokes. You could organize a a guessing game- think of “how many jelly beans are in this jar”? even with a small prize for the winner.
The possibilities are endless! Just make sure you don’t do anything that lands you in HR 😉