Most of Klaptrap's lines are pretty consistent in tone and emotion. I think the timestamped video links in the role characteristics are the best examples I can give of how Klaptrap should sound.

"MAN, what's a guy gotta do to find a decent SNACK around here?!"

"I can't speak for my entire species. But I get antsy when my tummy's rumbling. Lucky for you guys, I'm not hungry right now, so I won't try to eat you! Not like that chump I chased away a few nights ago. The nerve of that schmuck, crashing right in out of nowhere and waking me up while I had an empty stomach…"

"Huh. Whatdayaknow. Wish I would have caught 'em, then. Maybe I'd be a hero for catching a bad guy! Though, I guess if I had, there wouldn't've been much left of 'em to prove it, heheheh…"

"Alright, alright! I'm on the stand, happy? Haven't you already gotten enough of me after keeping watch all day and all night?! Go on, amscray! Yeesh!"

" I took a bite out of the cart right before it rode away. Almost broke my dentures!"

"Yeesh. This was the worst dine 'n' dash of my life…"