Okay, what did he roll?

An actual d20, haha

...I have to question whether that was an accident, or an "Accident".

My money is on "accident"

I think that was a "accident", too. If he wanted to put Laboon in a bad disposition toward him, he'd just have to keep punching.

It's Luke/Luffy. You never know.

Luffy attacks with talk no justu ... wait that’s Naruto ... em ... ah! Luffy activates special conqueror haki ability, The Colour of Compassion!

Even if you can hurt it, Island whales must have a crapton of HP.

Probably not any more than 3000. The largest devastation vermin does 25d10+24, a fairly comparable amount of damage, and has only 2,880 hp. I imagine this would still be a higher CR with its multiple attacks, though perhaps that's instead of the Devastation Beetle's Trample.

Typo in last panel - Seriously, not serioulsy