Float a raisin in Darth Vader’s coffee and ask him if the ship has a problem with rats.
Replace R2D2 with a Hoover and see if anyone notices.
Replace an Ewok with a Furby and see if anyone notices.
Superglue Hans Solo’s blaster in the holster.
Put a postit on Vader’s back that reads “Kick me and die”.
Reply to everything Yoda says with “Say that fast three times”.
Follow Luke around with a can of Lysol, spraying everything he touches.
Walk around behind Darth Vader imitating that sucking sound he makes.
Whenever he picks up a drinking glass, microphone, or any other cyndrilical object, pretend to choke and gasp for air.
Ask Leia if Luke’s or Han’s Lightsaber is bigger. (I KNOW, Han didn’t have a lightsaber, it’s a joke, get over it)
Ask Luke to see his lightsaber. Then wink.
Use a fellow Stormtrooper’s armor to fix that pesky PVC Pipe that’s been leaking in the bathroom.
Using the Force, move people’s seats out from under them, just as they’re sitting down.
Carve your name on Alderaan using the Death Star’s TurboLaser.
Tell Han the Odds.
My favorite was always to wait until somebody commented on how lovely the moon was tonight (or some such), then look worried and reply with “That’s no moon… that’s a space station!”
Yeah, it’s lame. I knew that.