I had a giant box delivered to work once.
It had a giant balloon in it, filled with tiny balloons.
When I opened the box the giant-balloon-filled-with-tiny-balloons floated out and up to the end of the ribbon, and we all looked at it for a moment and then I put it on the floor behind my desk and nobody mentioned it again.
I think we were all a bit surprised.
DH once had flowers delivered to me at work, but he was working abroad at the time and I was obviously out at work and not at home, so he had to send them there.
One of the other women in the office was clearly put out about it, my boss just said "oh shit, Julie will kill me" and had some flowers sent to her at her place of work, and everybody else ignored them.
It wasn't as embarrassing as the day a zebra finch flew in and I caught it and had a birdcage on my desk all day though.