This is a video of a dromedary camel eating some cacti with giant needles like they're ice cream cones. How does it do it? Probably the same way competitive eater L.A. Beast ate two cacti in this video, ten in this one (after downing four dried ghost peppers), and five light bulbs in this one: by trying hard and believing in itself. Per a zoologist:
Camel mouths are full of cone-shaped papillae that look like this [picture below]. These protrusions are partly keratinised - keratin being the hard stuff your nails are made out of - which makes them tough n' semi-rigid, feeling a bit like the middle of tupperware lids when you squish 'em. The plastic-ey cones not only help protect the mouth from internal damage - scratches, abrasions etc. - when they feed on thorns and other nasties, but they also manipulate the food to go down in one direction.
Worth mentioning that modern camels wouldn't be eating cactus like this in the wild either; instead it'd be scrubby, thorny acacia bushes and the like. They also likely do feel some pain and discomfort eating this stuff, as much of their mouths - particularly their lips - are very sensitive, despite the papillae. Being metal as f**k though, camels just get on with it.
Man, camels are even harder-core than I'd previously thought. And I already thought they were pretty hardcore on account of being able to survive so long without water and their willingness to spit at anything that pisses them off. I used to spit a lot, but my girlfriend made me stop because "It's gross," and, "Jesus, not in the restaurant!" For the record though I said no relish.
Keep going for a shot of the inside of a camel's mouth, and the video.
Thanks to Joseph A, who's always dreamed of eating a basketful of sewing needles.