Okay, so I need to put my dog down?

Well here's my story. I recently bought a pet dog for my girlfriend and myself, as it is our 9-month anniversary. I named him "Captain Falcon", hoping she would understand the reference (you know, FALCON PUNCH!). Unfortunately, she didn't understand the reference, so I have to put Captain, well, 'to sleep'. How should I do this? I don't own a gun, but I have plenty of blunt objects. Or maybe I should just start a little fire and playfully throw him in? I'm stumped here, kids. Any suggestions? Thanks in advance.