Sometimes, names are abject liars, and something that sounds harmless, or actually cute can be horrible. Probably the mascot of all things so much worse than they sound is the downright adorably-named Teddy Bear Cholla ( Cylindropuntia bigelovii ). Even the scientific name of this vegetable horror sounds cute: bigelovii. D’awwww.
Here’s a patch of them:

By Homer Edward Price (Teddy-Bear-Chollas-c Uploaded by Amada44) [CC BY 2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons
It’s wicked sharp needles.

Stan Shebs [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0) or CC BY-SA 2.5 (http://creativecommons.org/licenses/by-sa/2.5)], via Wikimedia Commons
Teddy Bear Chollas reproduce primarily through this process of harpooning and hitching rides on unfortunate animals, who transport the chunks to new locations until they can finally work the spines out. The cactus chunks can take root where they land, and a new Teddy Bear Cholla is born. They also flower and produce fruit with seeds in it though.
Teddy Bear Chollas, like many plants, can reproduce either sexually (with flowers and pollination) or asexually (cloning via pieces of the plant taking root). Cloning is much faster and more effective, but all the plants that root from pieces of a mother plant are genetically the same, and so all of them share the same vulnerabilities. That’s why genetic diversity in a species is so important. The more different versions of genes are available, the more chances there are to resist any one disease or other threat.
Like So:

A Wild Cholla Patch Appears! Most are clones of the mother plant, but a few are from seeds, and have other genes mixed in.

Although the parasite kills the mother plant and the clones, which were vulnerable to it, it doesn’t get the others.
Teddy Bear Cholla are very good at spearing and spreading.

By Jack Dykinga [CC BY-SA 2.0 (http://creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons
Teddy Bear Cholla are METAL.
Fortunately, we live outside their natural range. But, anyway, if you go to the desert Southwest of North America, keep an eye on the Cholla.