For some odd reason, one of the latest viral videos circulating around the Internet focuses on people putting cucumbers behind their cats and watching the cat freak out when they spot it behind them. While amusing, this can be traumatic for your cat.
First of all, cats could leap out of the way and hurt themselves or knock something over. Second of all, cats may think the cucumber is a snake so the sudden appearance of an object behind it could cause it emotional trauma.
As a general rule, if you wouldn’t want someone to do something to you, don’t do it to an animal, even if it’s your own cat.