Alright, well, here are my favorite captions from each user.
SMRPGFan- *insert Sephiroth joke here*
Professor Luigi- Bowser: IMA FIRIN' MEH LAZOR, BAH!
Breaths fireMario: Come on Bowser, almost 30 years and you still can't do it right.
Mark Jeevananthan- As Bowser tried to take a bite out of the Galaxy's biggest and hottest pizza slice, Mario stole the giant pepperoni.
Mariorockz! 
- Mario: Hi, Mario here with a new product, the "Fire-on"! Here's an example...... "Fire-on!"
(claps hands and Bowser blows fire)
Mario: "Fire-off!"
(claps hands and Bowser stops blowing)
Mario: "Fire-on!"
(claps hands and Bowser blows fire)
Mario: BUY ONE TODAY!
Only sold in the Mushroom Kingdom, keep away from curtainsMM Bro- Peach DID finally bake Bowser a galaxy-sized cake, and this was the aftermath.
superyoshi8- Bowser: Yeah, I built this whole castle for me to burn it down in a failed attempt to roast you.
Mario: Yeah, that's how it goes.
PSI Sex- Mario: Quick, SCREENSHOT POSE!
Bowser: BLARAGHGAAAGH -suck with fire in mouth-
MarioLuigiCombo- Mario: Whoa! Bowser! You need a Tic Tac!
Whiskers- Mario: Bowser! What did you have? One of those spicy enchiladas from Taco Bell? I told you those were bad for you! Now don't spew all over the place, you're making a mess.
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Voting ends on Monday, August 2nd, at 12:30 PM CST.