Iron Butt-Monkey

Film
The Three Stooges have suffered plenty of injuries that would maim or even kill a normal human being, like having bricks fall on their heads, being shot several times in the buttocks, falling from great heights, having a stick of dynamite go off in their pants, and that's only scratching the surface.

Although if you've got to be shot, the buttocks are pretty much the healthiest place to do it. No organs, very few major blood vessels, lots of force-absorbing muscle.

Except if you get hit with shrapnel in one of the iliac arteries and bleed out within minutes. It may be the healthiest spot, but still not healthy enough.

Curly seemed the most resilient - a common gag was to have Moe pound him over the head with a hammer or run a saw over his scalp, and the tool would be irreparably damaged.

Western Animation
Comic relief jerkass Earl of Lemongrab of Adventure Time. Thanks to his super-hard lemon candy skin, he has supercandyperson strength. He falls head-first out of the window of a castle and smashes his head into the ground hard enough to leave a big indentation in the earth, but he was fine. (Pissed-off, though.) Then, he fell from a tree and had a pretty nasty fall right on his back. Again, he was fine- just angry.

The title character from Courage the Cowardly Dog has taken many injuries and is shown to still be fine in the next scenes, even letting out a dazed laughter as if it was nothing. Eustace, however, has him rivaled for this trope, for he has suffered far worse injuries than Courage and is still alive in the next episode.

Ed, Edd n Eddy. Ed has dropped houses on Edd and Eddy, the Kankers' trailer fell on the Eds, a pile of garage sale junk fell on Ed, all three suffered spontaneous combustion after eating some jalapeno hot sauce, Ed zapped Edd with a static electricity bolt powerful enough to blow up the latter's house. If all that's not enough, all three once smashed into the sky, shattering into pieces.

Special mention goes to Eddy, seeing as he's the biggest butt monkey of the three; he's been beaten up more than anyone else on the show, had his arm smashed against a filing cabinet repeatedly, run through a thorn bush naked, been attacked by a psychotic rooster, trampled by hippos, been struck by lightning, shattered into bits like glass, had his hair used as a violin, had his head sucked into a vacuum, used as the ball in a giant set of Newton Balls, had his head smashed into a tree God knows how many times, been smashed on against a metal trailer like a super ball, had his head pecked by a chicken for twenty-four hours then shrunk, run over by a truck and a train, but for the most part walks it off.

Pretty much all the characters in Rocko's Modern Life have fallen to this trope at least once in an episode, Rocko being the occasional victim of this.

Steven Universe:

Amethyst gets way more physical abuse than any other character. Nine times out of ten she'll walk it off no problem.

Peridot suffers Wile E. Coyote-level trauma in "The Kindergarten Kid".

Steven: You don't poof easily, huh?

Peridot: [whilst under a boulder] Us Peridots are stronger than we look!note

Though it pales in comparison, Ronaldo has brushed off a number of comical injuries, which is especially notable given he's completely human. He once got in a fight with the Crystal Gems that realistically would have broken his hand and jaw, as well as possible his skull, neck, or back, then recovers instantly. Keep Beach City Weird mentions a refrigerator falling on top of him, whereupon his only concern was being stuck under it.

Time Squad: All three main characters; Larry has been electrocuted, smashed by a washing machine, been shot at, several times his body has been reduced to just a head, and has had his computer system scrambled by magnets. Otto gets frequently beat up by people from history, chased by a grizzly bear, viciously attacked by an evil My Little Pony (seriously), suffers from Tuddrussel's stunts, was crushed by a bookcase (off-screen), left in a hurricane, and was practically the resident buttmonkey at the orphanage. Tuddrussel takes a good amount for himself when it comes to getting beaten up by people, like Joan of Arc for example, has been slammed into the ground after destroying a giant fly monster, attacked by a lion, took on lava from the top of a volcano and really takes an equal amount as his comrades.