David Hasselhoff was auctioning some of his stuff to benefit the Starlight Foundation and one of those items was a gigantic replica of him from the SpongeBob Squarepants movie.
The massive model was borrowed by Jimmy Kimmel for his late night show.
Since the Kimmel Live team had a 14-foot David Hasselhoff for the day, they thought it'd be nice to have some fun with it.
They hid it in the alley behind their studios to surprise unsuspecting people when they turned round the corner.
Needless to say, the reactions to the giant Hasselhoff were priceless.
Have a look at the hilarious segment in the video above.