They were bright orange with the words LITTER BUG printed in large white upper-case letters on the lid, along with a large white arrow pointing inside, and had a circular cover that pivoted open by one edge of the lid. The name refers to litterbugs, a slang term used since the late 1940s for people who throw their trash on the ground in public.
In contrast to the usual meaning, the Litter Bug actually helped discourage people from littering, listening for anyone to mention they want to throw something away, moving close to them, and opening its lid in readiness.
On October 21, one of these mobile trashcans almost knocked Emmett Brown over as he was looking for somewhere to dispose of the Grays Sports Almanac which Marty McFly had bought from the Blast from the Past antique/memorabilia store.
However, Doc was distracted by the arrival of Officers Reese and Foley, who had recovered Jennifer Parker in the alleyway, and so didn't make use of the Litter Bug while it was there — throwing the almanac into a more traditional stationary trashcan instead, where it was found shortly after by Biff Tannen.
Behind the scenes
- The Litter Bug prop isn't seen clearly in the finished film: when it first appears behind Marty, it's quite far away from the camera; and when Doc approaches it, its base and means of traction are out of camera shot.
- The Litter Bug prop, albeit with a damaged lid, is now on show as part of the Back to the Future display in the NBCUniversal Experience at Universal Studios Hollywood, where it is labeled BACK TO THE FUTURE II (1989) Futuristic Trashcan.
- Robotic mobile trashcans like the Litter Bug featured in Back to the Future Part II have yet to appear on the streets of America.