It might not be the matchup people have thought about or possibly even care about…but then again they don't matter right now. What matters right now is Guy Fieri and Caillou (no last name like the alien child he is). In this matchup, I imagine Fieri waking up in Flavortown and feeling a chill in the air as if he can sense the close approach of Caillou's unhinged presence. Caillou on the other hand, started the day like he always does with somehow a full homemade breakfast with a side of his own narcissism that hurts his mother's mental health.
Both sides would prepare to meet one another but their origins only matter partly, what matters more is what they each bring to the table.
Assets in this fight would be crucial. I can only imagine that Guy Fieri would call on the supplies and backup support of the diners, drive-ins, and dives around the United States. With Caillou, his family has got to be somewhat reluctant. Each member in that household resembles the unease of the townspeople from the Twilight Zone episode "It's A Good Life" who tiptoe around a creepy kid with strong mental powers. Maybe the sense of having nothing to lose will be on Caillou's side, but then again he depends a little too much on those around him. Fieri on the other hand might have more at stake, but his tools would be great (and that's gotta include an insane car collection right?).
If assets and weapons of the physical kind were taken away, the fight between Caillou and Fieri would be weird as hell. I don't put it past Caillou to go balls to the wall when it comes to hand-to-hand combat, that crazy f@cker would rip a dude's face off so that he could spend more time with "mommy". So in saying all that, the element of surprise and moments of intensity would be on Caillou's side for sure. We might underestimate Caillou, but we're likely correct in an uphill battle against Fieri. Fieri is a comedian and chef in one person, but in a minute he would run Caillou over blasting 60s tunes from Chevy Camaro SS without a second thought. There's a calm and crazy energy in this type of fight (putting aside the animation vs reality dilemma). I'll post below who I think would win in this battle, but let us know in the comments who you think would defeat the other!