You'd need a bigger box, but what I used to do is wait until my cat was in a box, and then.....I'd close the box!!! Don't worry, these boxes aren't airtight. She can breathe just fine.

But then I'd go tell my girlfriend (who I lived with at the time) that (something she recently ordered) had arrived. That she should send it in for a return because something was wrong....

Inevitably she'd come in and open the top of the box (which was already visably open, so all she was doing was opening the flaps). And inside was our cat Karmalee.

Which, I'm sorry. I don't have pictures of Karmalee on my phone. It was 25 years ago.

But she'd switch from angry, to cute mode in an instant. Which is my kind of prank. Where they think something bad happened, but in reality nothing bad happened, and now heres a cute cat.