Pogo played around with this trope a lot, especially in its earlier days. The animals went back and forth between viewing carnivorism as no big deal ("I dunno, Pogo...sounds kinda good.") and treating it as cannibalism.
The prime example here is Albert the Alligator, who in the early days of the comic would sometimes end up swallowing smaller animals by accident (they were usually saved, though) and would sometimes be accused of eating someone if they went missing. He'd sometimes threaten to eat the small critters if they annoyed him, and at one point even chased after the villains with a knife and fork, as revenge when they'd tried to eat Pogo — but he never actually went through with it. He stopped doing this in the comic's later years, but he'd still cheerfully mooch off his friends and eating their food.
The villains of the comic were more openly carnivorous, especially Wiley Catt and Seminole Sam, who would at times try to cook and eat the smaller animals, such as Pogo.
The other characters would (in addition to cakes, biscuits and other types of snack food) eat fish, who were mostly portrayed as non-sentient...though in one very early story, Pogo and Howland Owl are getting into a discussion while fishing, resulting in the same fish getting pulled in and out of the water a number of times...until it asks, in an annoyed tone: "Is you fishin' or just hossin' around? Make up yo' minds! I ain't got all day!"
In a Far Side strip, a chicken serves her bedridden husband a bowl of soup, saying, "Quit complaining and eat it! First of all, chicken soup is good for a cold, and second, it's nobody we know."
Gary Larson seemed fond of exposing this trope. One strip has a cow saying to her friends "Hey, we really DO taste like chicken" after trying a hamburger; another has the cow's friends saying "You're SICK, Jessie! Sick, sick, sick!" while said cow is running a barbecue grill. Funny at age 12, rather disturbing now...
The Far Side also features the animal addiction-recovery organization "Maneaters Anonymous".
This idea is used in the same darkly humorous fashion in a Robot Chicken segment, where two bulls munch slowly on hamburgers made from their friend and commend how good he tastes.
The illustrated short story There's A Hair In My Dirt! by the same author, is an especially brutal mockery of this trope. The 'beautiful forest maiden' Harriet, on her way home from a stroll through the forest, encounters a snake attacking a mouse. She grabs a big stick and bashes the big bad vicious snake to death, then cuddles the poor helpless little mouse until it recovers, upon which she releases it back into the meadow. Good having triumphed over evil, the forest is now a safer place for all woodland creatures! Well...not quite. Turns out the mouse was carrying deadly diseases. As mice tend to do...which is why it's actually a good thing that snakes keep the population in check. And so 'one fine spring morning Harriet, delirious with fever, stumbled out of her little cottage, fell over, and died.'
There was a series of full-page color strips from Cows of Our Planet, and every age of evolution includes at least one cow-thing, leading to the future, where the whole world is ruled by cows. And there's a burger restaurant behind a wax museum full of butchers.
The straight version is played deliberately for laughs in Sherman's Lagoon, as part of its championship of 'uncute' critters: the two starring sharks eat other anthropomorphic fish regularly, usually after chatting for awhile. They also frequently go after humans — which they call "hairless beach apes" — as well, 'fishing' for them using lines cast onto the beach. Numerous strips discuss the best baits for the various types of human.
Played straight in Pearls Before Swine...except that the predator crocs are altogether too stupid to catch their prey, Zebra, even though he lives right next door. They survive in the meanwhile by devouring fried chicken and other fast food.
They doubled the fun when some lions moved into the house on the other side of Zebra and the wives are very competent hunters. Fortunately for Zebra, the lions went through a divorce and the husband scored big in the settlement. Got both the house and the wives have to ship a crate of meat each week.
Genius Bonus: Male lions don't hunt. Lionesses do all the work, and then the males bull in and take their fill (giving us a literal grounding in the phrase "lion's share"); the females and cubs can take from what's left when the males are done.
Pig apparently really likes bacon. He was kicked out of the Pig Fraternity for enjoying BLTs, which gave the first Pearls collection its title. At one point he's handed a packet of bacon and just by looking at it can identify his relatives... yet sees nothing wrong with eating it!
In Garfield, Garfield has eaten (or tried to) birds, fish, and flowers that are often shown to be as intelligent as he is even after holding conversations with them, and also has no compunctions whatsoever about squashing talking spiders (and their grieving families.) For the most part, Garfield will eat anything but mice, established within the first week of the strip's creation. ("Show me a good mouser, and I'll show you a cat with bad breath.") He also abhors spinach (especially cooked spinach) and raisins (even in cookies). A certain strip has Garfield facing the ghosts of all the animals he's eaten, including what looks like a cow or a horse. (It's probably meant to be a cow [beef lasagna], given its split hooves, although if he's ever actually eaten cat food, a horse might be possible as well.) Meanwhile, the protagonists of U.S. Acres are herbivores, with predatory animals appearing only as villains, unless you count Booker's fruitless pursuit of a worm which sometimes appears more intelligent than he is — although, in "The Worm Turns", Sheldon the ambulatory egg mentions that he's planning to have quiche for dinner...
The front cover of Vol. 4 has Garfield about to have two eggs sunny-side up (truly a meal of epic proportions), when he sees that Booker, wings crossed and glaring at him, is standing there with Sheldon. The back cover has him running with his plate as Sheldon chases him, Booker riding on top and brandishing a fork...