hedgehog
green prickly caterpillar
If you mean spinal columns, yes pandas have them. If you mean prickly spines, such as the porcupine or hedgehogs have, the answer is no.
It depends on which cactus is being eaten. Some are poisonous while others are beneficial and highly nutritious. Prickly pear pads are a winner as long as you get the right type. I have read online that there is a poisonous strain of prickly pear that has an orange coloring in its spines. Some prickly pear has been selectively reproduced to eliminate the spines and it is used as a human and animal food staple in desert areas, such as Mexico.
If you stuck your finger into a prickly pear cactus, you could get stuck with one of the spines. You could also possibly be bitten by a spider who likes to make their webs in the prickly pear.
Prickly pear cactus can reproduce by seed, root division and by cuttings from the paddles being individually rooted.
It curls up in a ball, protecting its face and front which are vital parts. Curling into a ball also causes the prickly spines to protrude more. These spines act as a defense.
They're vertebrates, they're born that way. An animal looking like that and living like that has to have some sort of supporting structure, and for the hedgehog it's a spine. Or maybe you're thinking of the things that make them prickly, not the backbone. There are plenty of animals out there who would make themselves a meal of a fairly slow and harmless animal as a hedgehog, so the spines developed as a defence. If threatened the hedgehog curls up into a prickly ball, and anyone trying to bite or claw it end up getting hurt. THe hedgehog ended up taking that route instad of developing an ability to run, hide or bite back.
Hedgehogs live in parts of the Sahara and have spines.
Basically it means "hedgehog", an animal that is covered with prickly spines, but by association it can also mean a "prickly natured" person, or someone with spiky hair. There were also sea defenses against invasion by landing-craft called "hedgehogs" made of sharp-pointed sticking-out angle-iron welded together.
Hedgehog
The echidna is an animal which lays eggs. The echidna is covered in spines. Like platypuses, echidnas are monotremes, or egg-laying mammals.
Hairy stems with dark green, narrow leaves toothed on the margins, bearing a prickly spine, grows to 2 feet. Pale yellow flower heads blooming at the top of the stem, covered with prickly spines.